ExportSql.php

<?php
/**
 * Set of functions used to build SQL dumps of tables
 */

declare(strict_types=1);

namespace PhpMyAdmin\Plugins\Export;

use PhpMyAdmin\Charsets;
use PhpMyAdmin\Config;
use PhpMyAdmin\Current;
use PhpMyAdmin\Database\Events;
use PhpMyAdmin\Database\Routines;
use PhpMyAdmin\DatabaseInterface;
use PhpMyAdmin\Dbal\ConnectionType;
use PhpMyAdmin\Plugins\ExportPlugin;
use PhpMyAdmin\Properties\Options\Groups\OptionsPropertyMainGroup;
use PhpMyAdmin\Properties\Options\Groups\OptionsPropertyRootGroup;
use PhpMyAdmin\Properties\Options\Groups\OptionsPropertySubgroup;
use PhpMyAdmin\Properties\Options\Items\BoolPropertyItem;
use PhpMyAdmin\Properties\Options\Items\MessageOnlyPropertyItem;
use PhpMyAdmin\Properties\Options\Items\NumberPropertyItem;
use PhpMyAdmin\Properties\Options\Items\RadioPropertyItem;
use PhpMyAdmin\Properties\Options\Items\SelectPropertyItem;
use PhpMyAdmin\Properties\Options\Items\TextPropertyItem;
use PhpMyAdmin\Properties\Plugins\ExportPluginProperties;
use PhpMyAdmin\SqlParser\Components\CreateDefinition;
use PhpMyAdmin\SqlParser\Context;
use PhpMyAdmin\SqlParser\Parser;
use PhpMyAdmin\SqlParser\Statements\CreateStatement;
use PhpMyAdmin\SqlParser\Token;
use PhpMyAdmin\SqlParser\TokenType;
use PhpMyAdmin\Triggers\Triggers;
use PhpMyAdmin\UniqueCondition;
use PhpMyAdmin\Util;
use PhpMyAdmin\Version;

use function __;
use function array_keys;
use function bin2hex;
use function defined;
use function explode;
use function implode;
use function in_array;
use function is_array;
use function mb_strlen;
use function mb_strpos;
use function mb_substr;
use function preg_quote;
use function preg_replace;
use function preg_split;
use function sprintf;
use function str_contains;
use function str_repeat;
use function str_replace;
use function strtotime;
use function strtoupper;
use function trigger_error;

use const E_USER_ERROR;
use const PHP_VERSION;

/**
 * Handles the export for the SQL class
 */
class ExportSql extends ExportPlugin
{
    /**
     * Whether charset header was sent.
     */
    private bool $sentCharset = false;

    private bool $useSqlBackquotes = false;

    private string $sqlViews = '';

    /** @psalm-return non-empty-lowercase-string */
    public function getName(): string
    {
        return 'sql';
    }

    public function useSqlBackquotes(bool $useSqlBackquotes): void
    {
        $this->useSqlBackquotes = $useSqlBackquotes;
    }

    protected function setProperties(): ExportPluginProperties
    {
        $GLOBALS['plugin_param'] ??= null;

        $hideSql = false;
        $hideStructure = false;
        if ($GLOBALS['plugin_param']['export_type'] === 'table' && ! $GLOBALS['plugin_param']['single_table']) {
            $hideStructure = true;
            $hideSql = true;
        }

        // In case we have `raw_query` parameter set,
        // we initialize SQL option
        if (isset($_REQUEST['raw_query'])) {
            $hideStructure = false;
            $hideSql = false;
        }

        $exportPluginProperties = new ExportPluginProperties();
        $exportPluginProperties->setText('SQL');
        $exportPluginProperties->setExtension('sql');
        $exportPluginProperties->setMimeType('text/x-sql');

        if ($hideSql) {
            return $exportPluginProperties;
        }

        $exportPluginProperties->setOptionsText(__('Options'));

        // create the root group that will be the options field for
        // $exportPluginProperties
        // this will be shown as "Format specific options"
        $exportSpecificOptions = new OptionsPropertyRootGroup('Format Specific Options');

        // general options main group
        $generalOptions = new OptionsPropertyMainGroup('general_opts');

        // comments
        $subgroup = new OptionsPropertySubgroup('include_comments');
        $leaf = new BoolPropertyItem(
            'include_comments',
            __(
                'Display comments <i>(includes info such as export timestamp, PHP version, and server version)</i>',
            ),
        );
        $subgroup->setSubgroupHeader($leaf);

        $leaf = new TextPropertyItem(
            'header_comment',
            __('Additional custom header comment (\n splits lines):'),
        );
        $subgroup->addProperty($leaf);
        $leaf = new BoolPropertyItem(
            'dates',
            __(
                'Include a timestamp of when databases were created, last updated, and last checked',
            ),
        );
        $subgroup->addProperty($leaf);
        $relationParameters = $this->relation->getRelationParameters();
        if ($relationParameters->relationFeature !== null) {
            $leaf = new BoolPropertyItem(
                'relation',
                __('Display foreign key relationships'),
            );
            $subgroup->addProperty($leaf);
        }

        if ($relationParameters->browserTransformationFeature !== null) {
            $leaf = new BoolPropertyItem(
                'mime',
                __('Display media types'),
            );
            $subgroup->addProperty($leaf);
        }

        $generalOptions->addProperty($subgroup);

        // enclose in a transaction
        $leaf = new BoolPropertyItem(
            'use_transaction',
            __('Enclose export in a transaction'),
        );
        $leaf->setDoc(
            ['programs', 'mysqldump', 'option_mysqldump_single-transaction'],
        );
        $generalOptions->addProperty($leaf);

        // disable foreign key checks
        $leaf = new BoolPropertyItem(
            'disable_fk',
            __('Disable foreign key checks'),
        );
        $leaf->setDoc(
            ['manual_MySQL_Database_Administration', 'server-system-variables', 'sysvar_foreign_key_checks'],
        );
        $generalOptions->addProperty($leaf);

        // export views as tables
        $leaf = new BoolPropertyItem(
            'views_as_tables',
            __('Export views as tables'),
        );
        $generalOptions->addProperty($leaf);

        // export metadata
        $leaf = new BoolPropertyItem(
            'metadata',
            __('Export metadata'),
        );
        $generalOptions->addProperty($leaf);

        $dbi = DatabaseInterface::getInstance();
        // compatibility maximization
        $compats = $dbi->getCompatibilities();
        if ($compats !== []) {
            $this->addCompatOptions($compats, $generalOptions);
        }

        // what to dump (structure/data/both)
        $subgroup = new OptionsPropertySubgroup(
            'dump_table',
            __('Dump table'),
        );
        $leaf = new RadioPropertyItem('structure_or_data');
        $leaf->setValues(
            ['structure' => __('structure'), 'data' => __('data'), 'structure_and_data' => __('structure and data')],
        );
        $subgroup->setSubgroupHeader($leaf);
        $generalOptions->addProperty($subgroup);

        // add the main group to the root group
        $exportSpecificOptions->addProperty($generalOptions);

        // structure options main group
        if (! $hideStructure) {
            $structureOptions = new OptionsPropertyMainGroup(
                'structure',
                __('Object creation options'),
            );
            $structureOptions->setForce('data');

            // begin SQL Statements
            $subgroup = new OptionsPropertySubgroup();
            $leaf = new MessageOnlyPropertyItem(
                'add_statements',
                __('Add statements:'),
            );
            $subgroup->setSubgroupHeader($leaf);

            // server export options
            if ($GLOBALS['plugin_param']['export_type'] === 'server') {
                $leaf = new BoolPropertyItem(
                    'drop_database',
                    sprintf(__('Add %s statement'), '<code>DROP DATABASE IF EXISTS</code>'),
                );
                $subgroup->addProperty($leaf);
            }

            if ($GLOBALS['plugin_param']['export_type'] === 'database') {
                $createClause = '<code>CREATE DATABASE / USE</code>';
                $leaf = new BoolPropertyItem(
                    'create_database',
                    sprintf(__('Add %s statement'), $createClause),
                );
                $subgroup->addProperty($leaf);
            }

            if ($GLOBALS['plugin_param']['export_type'] === 'table') {
                $dropClause = $dbi->getTable(Current::$database, Current::$table)->isView()
                    ? '<code>DROP VIEW</code>'
                    : '<code>DROP TABLE</code>';
            } else {
                $dropClause = '<code>DROP TABLE / VIEW / PROCEDURE / FUNCTION / EVENT</code>';
            }

            $dropClause .= '<code> / TRIGGER</code>';

            $leaf = new BoolPropertyItem(
                'drop_table',
                sprintf(__('Add %s statement'), $dropClause),
            );
            $subgroup->addProperty($leaf);

            $subgroupCreateTable = new OptionsPropertySubgroup();

            // Add table structure option
            $leaf = new BoolPropertyItem(
                'create_table',
                sprintf(__('Add %s statement'), '<code>CREATE TABLE</code>'),
            );
            $subgroupCreateTable->setSubgroupHeader($leaf);

            $leaf = new BoolPropertyItem(
                'if_not_exists',
                '<code>IF NOT EXISTS</code> ' . __(
                    '(less efficient as indexes will be generated during table creation)',
                ),
            );
            $subgroupCreateTable->addProperty($leaf);

            $leaf = new BoolPropertyItem(
                'auto_increment',
                sprintf(__('%s value'), '<code>AUTO_INCREMENT</code>'),
            );
            $subgroupCreateTable->addProperty($leaf);

            $subgroup->addProperty($subgroupCreateTable);

            // Add view option
            $subgroupCreateView = new OptionsPropertySubgroup();
            $leaf = new BoolPropertyItem(
                'create_view',
                sprintf(__('Add %s statement'), '<code>CREATE VIEW</code>'),
            );
            $subgroupCreateView->setSubgroupHeader($leaf);

            $leaf = new BoolPropertyItem(
                'simple_view_export',
                /* l10n: Allow simplifying exported view syntax to only "CREATE VIEW" */
                __('Use simple view export'),
            );
            $subgroupCreateView->addProperty($leaf);

            $leaf = new BoolPropertyItem(
                'view_current_user',
                __('Exclude definition of current user'),
            );
            $subgroupCreateView->addProperty($leaf);

            $leaf = new BoolPropertyItem(
                'or_replace_view',
                sprintf(__('%s view'), '<code>OR REPLACE</code>'),
            );
            $subgroupCreateView->addProperty($leaf);

            $subgroup->addProperty($subgroupCreateView);

            $leaf = new BoolPropertyItem(
                'procedure_function',
                sprintf(
                    __('Add %s statement'),
                    '<code>CREATE PROCEDURE / FUNCTION / EVENT</code>',
                ),
            );
            $subgroup->addProperty($leaf);

            // Add triggers option
            $leaf = new BoolPropertyItem(
                'create_trigger',
                sprintf(__('Add %s statement'), '<code>CREATE TRIGGER</code>'),
            );
            $subgroup->addProperty($leaf);

            $structureOptions->addProperty($subgroup);

            $leaf = new BoolPropertyItem(
                'backquotes',
                __(
                    'Enclose table and column names with backquotes '
                    . '<i>(Protects column and table names formed with'
                    . ' special characters or keywords)</i>',
                ),
            );

            $structureOptions->addProperty($leaf);

            // add the main group to the root group
            $exportSpecificOptions->addProperty($structureOptions);
        }

        // begin Data options
        $dataOptions = new OptionsPropertyMainGroup(
            'data',
            __('Data creation options'),
        );
        $dataOptions->setForce('structure');
        $leaf = new BoolPropertyItem(
            'truncate',
            __('Truncate table before insert'),
        );
        $dataOptions->addProperty($leaf);

        // begin SQL Statements
        $subgroup = new OptionsPropertySubgroup();
        $leaf = new MessageOnlyPropertyItem(
            __('Instead of <code>INSERT</code> statements, use:'),
        );
        $subgroup->setSubgroupHeader($leaf);

        $leaf = new BoolPropertyItem(
            'delayed',
            __('<code>INSERT DELAYED</code> statements'),
        );
        $leaf->setDoc(
            ['manual_MySQL_Database_Administration', 'insert_delayed'],
        );
        $subgroup->addProperty($leaf);

        $leaf = new BoolPropertyItem(
            'ignore',
            __('<code>INSERT IGNORE</code> statements'),
        );
        $leaf->setDoc(
            ['manual_MySQL_Database_Administration', 'insert'],
        );
        $subgroup->addProperty($leaf);
        $dataOptions->addProperty($subgroup);

        // Function to use when dumping dat
        $leaf = new SelectPropertyItem(
            'type',
            __('Function to use when dumping data:'),
        );
        $leaf->setValues(
            ['INSERT' => 'INSERT', 'UPDATE' => 'UPDATE', 'REPLACE' => 'REPLACE'],
        );
        $dataOptions->addProperty($leaf);

        /* Syntax to use when inserting data */
        $subgroup = new OptionsPropertySubgroup();
        $leaf = new MessageOnlyPropertyItem(
            null,
            __('Syntax to use when inserting data:'),
        );
        $subgroup->setSubgroupHeader($leaf);
        $leaf = new RadioPropertyItem(
            'insert_syntax',
            __('<code>INSERT IGNORE</code> statements'),
        );
        $leaf->setValues(
            [
                'complete' => __(
                    'include column names in every <code>INSERT</code> statement'
                    . ' <br> &nbsp; &nbsp; &nbsp; Example: <code>INSERT INTO'
                    . ' tbl_name (col_A,col_B,col_C) VALUES (1,2,3)</code>',
                ),
                'extended' => __(
                    'insert multiple rows in every <code>INSERT</code> statement'
                    . '<br> &nbsp; &nbsp; &nbsp; Example: <code>INSERT INTO'
                    . ' tbl_name VALUES (1,2,3), (4,5,6), (7,8,9)</code>',
                ),
                'both' => __(
                    'both of the above<br> &nbsp; &nbsp; &nbsp; Example:'
                    . ' <code>INSERT INTO tbl_name (col_A,col_B,col_C) VALUES'
                    . ' (1,2,3), (4,5,6), (7,8,9)</code>',
                ),
                'none' => __(
                    'neither of the above<br> &nbsp; &nbsp; &nbsp; Example:'
                    . ' <code>INSERT INTO tbl_name VALUES (1,2,3)</code>',
                ),
            ],
        );
        $subgroup->addProperty($leaf);
        $dataOptions->addProperty($subgroup);

        // Max length of query
        $leaf = new NumberPropertyItem(
            'max_query_size',
            __('Maximal length of created query'),
        );
        $dataOptions->addProperty($leaf);

        // Dump binary columns in hexadecimal
        $leaf = new BoolPropertyItem(
            'hex_for_binary',
            __(
                'Dump binary columns in hexadecimal notation <i>(for example, "abc" becomes 0x616263)</i>',
            ),
        );
        $dataOptions->addProperty($leaf);

        // Dump time in UTC
        $leaf = new BoolPropertyItem(
            'utc_time',
            __(
                'Dump TIMESTAMP columns in UTC <i>(enables TIMESTAMP columns'
                . ' to be dumped and reloaded between servers in different'
                . ' time zones)</i>',
            ),
        );
        $dataOptions->addProperty($leaf);

        // add the main group to the root group
        $exportSpecificOptions->addProperty($dataOptions);

        // set the options for the export plugin property item
        $exportPluginProperties->setOptions($exportSpecificOptions);

        return $exportPluginProperties;
    }

    /**
     * Generates SQL for routines export
     *
     * @param string   $db        Database
     * @param mixed[]  $aliases   Aliases of db/table/columns
     * @param string   $name      Verbose name of exported routine
     * @param string[] $routines  List of routines to export
     * @param string   $delimiter Delimiter to use in SQL
     * @psalm-param 'FUNCTION'|'PROCEDURE' $type
     *
     * @return string SQL query
     */
    protected function exportRoutineSQL(
        string $db,
        array $aliases,
        string $type,
        string $name,
        array $routines,
        string $delimiter,
    ): string {
        $text = $this->exportComment()
            . $this->exportComment($name)
            . $this->exportComment();

        $usedAlias = false;
        $procQuery = '';

        foreach ($routines as $routine) {
            if (! empty($GLOBALS['sql_drop_table'])) {
                $procQuery .= 'DROP ' . $type . ' IF EXISTS '
                    . Util::backquote($routine)
                    . $delimiter . "\n";
            }

            $dbi = DatabaseInterface::getInstance();
            if ($type === 'FUNCTION') {
                $definition = Routines::getFunctionDefinition($dbi, $db, $routine);
            } else {
                $definition = Routines::getProcedureDefinition($dbi, $db, $routine);
            }

            $createQuery = $this->replaceWithAliases($delimiter, $definition, $aliases, $db, $flag);
            if ($createQuery !== '' && Config::getInstance()->settings['Export']['remove_definer_from_definitions']) {
                // Remove definer clause from routine definitions
                $parser = new Parser('DELIMITER ' . $delimiter . "\n" . $createQuery);
                $statement = $parser->statements[0];
                $statement->options->remove('DEFINER');
                $createQuery = $statement->build();
            }

            // One warning per database
            if ($flag) {
                $usedAlias = true;
            }

            $procQuery .= $createQuery . $delimiter . "\n\n";
        }

        if ($usedAlias) {
            $text .= $this->exportComment(
                __('It appears your database uses routines;'),
            )
            . $this->exportComment(
                __('alias export may not work reliably in all cases.'),
            )
            . $this->exportComment();
        }

        $text .= $procQuery;

        return $text;
    }

    /**
     * Exports routines (procedures and functions)
     *
     * @param string  $db      Database
     * @param mixed[] $aliases Aliases of db/table/columns
     */
    public function exportRoutines(string $db, array $aliases = []): bool
    {
        $dbAlias = $db;
        $this->initAlias($aliases, $dbAlias);

        $text = '';
        $delimiter = '$$';

        $dbi = DatabaseInterface::getInstance();
        $procedureNames = Routines::getProcedureNames($dbi, $db);
        $functionNames = Routines::getFunctionNames($dbi, $db);

        if ($procedureNames || $functionNames) {
            $text .= "\n"
                . 'DELIMITER ' . $delimiter . "\n";

            if ($procedureNames !== []) {
                $text .= $this->exportRoutineSQL(
                    $db,
                    $aliases,
                    'PROCEDURE',
                    __('Procedures'),
                    $procedureNames,
                    $delimiter,
                );
            }

            if ($functionNames !== []) {
                $text .= $this->exportRoutineSQL(
                    $db,
                    $aliases,
                    'FUNCTION',
                    __('Functions'),
                    $functionNames,
                    $delimiter,
                );
            }

            $text .= 'DELIMITER ;' . "\n";
        }

        if ($text !== '') {
            return $this->export->outputHandler($text);
        }

        return false;
    }

    /**
     * Possibly outputs comment
     *
     * @param string $text Text of comment
     *
     * @return string The formatted comment
     */
    private function exportComment(string $text = ''): string
    {
        if (isset($GLOBALS['sql_include_comments']) && $GLOBALS['sql_include_comments']) {
            // see https://dev.mysql.com/doc/refman/5.0/en/ansi-diff-comments.html
            if ($text === '') {
                return '--' . "\n";
            }

            $lines = preg_split("/\\r\\n|\\r|\\n/", $text);
            if ($lines === false) {
                return '--' . "\n";
            }

            $result = [];
            foreach ($lines as $line) {
                $result[] = '-- ' . $line . "\n";
            }

            return implode('', $result);
        }

        return '';
    }

    /**
     * Possibly outputs CRLF
     *
     * @return string crlf or nothing
     */
    private function possibleCRLF(): string
    {
        if (isset($GLOBALS['sql_include_comments']) && $GLOBALS['sql_include_comments']) {
            return "\n";
        }

        return '';
    }

    /**
     * Outputs export footer
     */
    public function exportFooter(): bool
    {
        $foot = '';

        if (isset($GLOBALS['sql_disable_fk'])) {
            $foot .= 'SET FOREIGN_KEY_CHECKS=1;' . "\n";
        }

        if (isset($GLOBALS['sql_use_transaction'])) {
            $foot .= 'COMMIT;' . "\n";
        }

        // restore connection settings
        if ($this->sentCharset) {
            $foot .= "\n"
                . '/*!40101 SET CHARACTER_SET_CLIENT=@OLD_CHARACTER_SET_CLIENT */;'
                . "\n"
                . '/*!40101 SET CHARACTER_SET_RESULTS=@OLD_CHARACTER_SET_RESULTS */;'
                . "\n"
                . '/*!40101 SET COLLATION_CONNECTION=@OLD_COLLATION_CONNECTION */;'
                . "\n";
            $this->sentCharset = false;
        }

        /* Restore timezone */
        if (isset($GLOBALS['sql_utc_time']) && $GLOBALS['sql_utc_time']) {
            DatabaseInterface::getInstance()->query('SET time_zone = "' . $GLOBALS['old_tz'] . '"');
        }

        return $this->export->outputHandler($foot);
    }

    /**
     * Outputs export header. It is the first method to be called, so all
     * the required variables are initialized here.
     */
    public function exportHeader(): bool
    {
        $dbi = DatabaseInterface::getInstance();
        if (isset($GLOBALS['sql_compatibility'])) {
            $tmpCompat = $GLOBALS['sql_compatibility'];
            if ($tmpCompat === 'NONE') {
                $tmpCompat = '';
            }

            $dbi->tryQuery('SET SQL_MODE="' . $tmpCompat . '"');
            unset($tmpCompat);
        }

        $head = $this->exportComment('phpMyAdmin SQL Dump')
            . $this->exportComment('version ' . Version::VERSION)
            . $this->exportComment('https://www.phpmyadmin.net/')
            . $this->exportComment();
        $config = Config::getInstance();
        $hostString = __('Host:') . ' ' . $config->selectedServer['host'];
        if (! empty($config->selectedServer['port'])) {
            $hostString .= ':' . $config->selectedServer['port'];
        }

        $head .= $this->exportComment($hostString);
        $head .= $this->exportComment(
            __('Generation Time:') . ' '
            . Util::localisedDate(),
        )
        . $this->exportComment(
            __('Server version:') . ' ' . $dbi->getVersionString(),
        )
        . $this->exportComment(__('PHP Version:') . ' ' . PHP_VERSION)
        . $this->possibleCRLF();

        if (! empty($GLOBALS['sql_header_comment'])) {
            // '\n' is not a newline (like "\n" would be), it's the characters
            // backslash and n, as explained on the export interface
            $lines = explode('\n', $GLOBALS['sql_header_comment']);
            $head .= $this->exportComment();
            foreach ($lines as $oneLine) {
                $head .= $this->exportComment($oneLine);
            }

            $head .= $this->exportComment();
        }

        if (isset($GLOBALS['sql_disable_fk'])) {
            $head .= 'SET FOREIGN_KEY_CHECKS=0;' . "\n";
        }

        // We want exported AUTO_INCREMENT columns to have still same value,
        // do this only for recent MySQL exports
        if (! isset($GLOBALS['sql_compatibility']) || $GLOBALS['sql_compatibility'] === 'NONE') {
            $head .= 'SET SQL_MODE = "NO_AUTO_VALUE_ON_ZERO";' . "\n";
        }

        if (isset($GLOBALS['sql_use_transaction'])) {
            $head .= 'START TRANSACTION;' . "\n";
        }

        /* Change timezone if we should export timestamps in UTC */
        if (isset($GLOBALS['sql_utc_time']) && $GLOBALS['sql_utc_time']) {
            $head .= 'SET time_zone = "+00:00";' . "\n";
            $GLOBALS['old_tz'] = $dbi
                ->fetchValue('SELECT @@session.time_zone');
            $dbi->query('SET time_zone = "+00:00"');
        }

        $head .= $this->possibleCRLF();

        if (! empty($GLOBALS['asfile'])) {
            // we are saving as file, therefore we provide charset information
            // so that a utility like the mysql client can interpret
            // the file correctly
            if (isset($GLOBALS['charset'], Charsets::$mysqlCharsetMap[$GLOBALS['charset']])) {
                // we got a charset from the export dialog
                $setNames = Charsets::$mysqlCharsetMap[$GLOBALS['charset']];
            } else {
                // by default we use the connection charset
                $setNames = Charsets::$mysqlCharsetMap['utf-8'];
            }

            if ($setNames === 'utf8') {
                $setNames = $dbi->getDefaultCharset();
            }

            $head .= "\n"
                . '/*!40101 SET @OLD_CHARACTER_SET_CLIENT='
                . '@@CHARACTER_SET_CLIENT */;' . "\n"
                . '/*!40101 SET @OLD_CHARACTER_SET_RESULTS='
                . '@@CHARACTER_SET_RESULTS */;' . "\n"
                . '/*!40101 SET @OLD_COLLATION_CONNECTION='
                . '@@COLLATION_CONNECTION */;' . "\n"
                . '/*!40101 SET NAMES ' . $setNames . ' */;' . "\n\n";
            $this->sentCharset = true;
        }

        return $this->export->outputHandler($head);
    }

    /**
     * Outputs CREATE DATABASE statement
     *
     * @param string $db         Database name
     * @param string $exportType 'server', 'database', 'table'
     * @param string $dbAlias    Aliases of db
     */
    public function exportDBCreate(string $db, string $exportType, string $dbAlias = ''): bool
    {
        if ($dbAlias === '') {
            $dbAlias = $db;
        }

        $compat = $GLOBALS['sql_compatibility'] ?? 'NONE';

        $exportStructure = ! isset($GLOBALS['sql_structure_or_data'])
            || in_array($GLOBALS['sql_structure_or_data'], ['structure', 'structure_and_data'], true);
        if ($exportStructure && isset($GLOBALS['sql_drop_database'])) {
            if (
                ! $this->export->outputHandler(
                    'DROP DATABASE IF EXISTS '
                    . Util::backquoteCompat(
                        $dbAlias,
                        $compat,
                        $this->useSqlBackquotes,
                    )
                    . ';' . "\n",
                )
            ) {
                return false;
            }
        }

        if ($exportType === 'database' && ! isset($GLOBALS['sql_create_database'])) {
            return true;
        }

        $createQuery = 'CREATE DATABASE IF NOT EXISTS '
            . Util::backquoteCompat($dbAlias, $compat, $this->useSqlBackquotes);
        $collation = DatabaseInterface::getInstance()->getDbCollation($db);
        if (str_contains($collation, '_')) {
            $createQuery .= ' DEFAULT CHARACTER SET '
                . mb_substr(
                    $collation,
                    0,
                    (int) mb_strpos($collation, '_'),
                )
                . ' COLLATE ' . $collation;
        } else {
            $createQuery .= ' DEFAULT CHARACTER SET ' . $collation;
        }

        $createQuery .= ';' . "\n";
        if (! $this->export->outputHandler($createQuery)) {
            return false;
        }

        return $this->exportUseStatement($dbAlias, $compat);
    }

    /**
     * Outputs USE statement
     *
     * @param string $db     db to use
     * @param string $compat sql compatibility
     */
    private function exportUseStatement(string $db, string $compat): bool
    {
        if ($compat === 'NONE') {
            return $this->export->outputHandler(
                'USE '
                . Util::backquoteCompat(
                    $db,
                    $compat,
                    $this->useSqlBackquotes,
                )
                . ';' . "\n",
            );
        }

        return $this->export->outputHandler('USE ' . $db . ';' . "\n");
    }

    /**
     * Outputs database header
     *
     * @param string $db      Database name
     * @param string $dbAlias Alias of db
     */
    public function exportDBHeader(string $db, string $dbAlias = ''): bool
    {
        if ($dbAlias === '') {
            $dbAlias = $db;
        }

        $compat = $GLOBALS['sql_compatibility'] ?? 'NONE';

        $head = $this->exportComment()
            . $this->exportComment(
                __('Database:') . ' '
                . Util::backquoteCompat(
                    $dbAlias,
                    $compat,
                    $this->useSqlBackquotes,
                ),
            )
            . $this->exportComment();

        return $this->export->outputHandler($head);
    }

    /**
     * Outputs database footer
     *
     * @param string $db Database name
     */
    public function exportDBFooter(string $db): bool
    {
        $result = true;

        //add indexes to the sql dump file
        if (isset($GLOBALS['sql_indexes'])) {
            $result = $this->export->outputHandler($GLOBALS['sql_indexes']);
            unset($GLOBALS['sql_indexes']);
        }

        //add auto increments to the sql dump file
        if (isset($GLOBALS['sql_auto_increments'])) {
            $result = $this->export->outputHandler($GLOBALS['sql_auto_increments']);
            unset($GLOBALS['sql_auto_increments']);
        }

        //add views to the sql dump file
        if ($this->sqlViews !== '') {
            $result = $this->export->outputHandler($this->sqlViews);
            $this->sqlViews = '';
        }

        //add constraints to the sql dump file
        if (isset($GLOBALS['sql_constraints'])) {
            $result = $this->export->outputHandler($GLOBALS['sql_constraints']);
            unset($GLOBALS['sql_constraints']);
        }

        return $result;
    }

    /**
     * Exports events
     *
     * @param string $db Database
     */
    public function exportEvents(string $db): bool
    {
        $text = '';
        $delimiter = '$$';

        $dbi = DatabaseInterface::getInstance();
        $eventNames = $dbi->fetchResult(
            'SELECT EVENT_NAME FROM information_schema.EVENTS WHERE'
            . ' EVENT_SCHEMA= ' . $dbi->quoteString($db),
        );

        if ($eventNames !== []) {
            $text .= "\n"
                . 'DELIMITER ' . $delimiter . "\n";

            $text .= $this->exportComment()
                . $this->exportComment(__('Events'))
                . $this->exportComment();

            foreach ($eventNames as $eventName) {
                if (! empty($GLOBALS['sql_drop_table'])) {
                    $text .= 'DROP EVENT IF EXISTS '
                        . Util::backquote($eventName)
                        . $delimiter . "\n";
                }

                $eventDef = Events::getDefinition($dbi, $db, $eventName);
                if (
                    $eventDef !== null
                    && $eventDef !== ''
                    && Config::getInstance()->settings['Export']['remove_definer_from_definitions']
                ) {
                    // remove definer clause from the event definition
                    $parser = new Parser('DELIMITER ' . $delimiter . "\n" . $eventDef);
                    $statement = $parser->statements[0];
                    $statement->options->remove('DEFINER');
                    $eventDef = $statement->build();
                }

                $text .= $eventDef . $delimiter . "\n\n";
            }

            $text .= 'DELIMITER ;' . "\n";
        }

        if ($text !== '') {
            return $this->export->outputHandler($text);
        }

        return false;
    }

    /**
     * Exports metadata from Configuration Storage
     *
     * @param string          $db            database being exported
     * @param string|string[] $tables        table(s) being exported
     * @param string[]        $metadataTypes types of metadata to export
     */
    public function exportMetadata(
        string $db,
        string|array $tables,
        array $metadataTypes,
    ): bool {
        $relationParameters = $this->relation->getRelationParameters();
        if ($relationParameters->db === null) {
            return true;
        }

        $comment = $this->possibleCRLF()
            . $this->possibleCRLF()
            . $this->exportComment()
            . $this->exportComment(__('Metadata'))
            . $this->exportComment();
        if (! $this->export->outputHandler($comment)) {
            return false;
        }

        if (! $this->exportUseStatement((string) $relationParameters->db, $GLOBALS['sql_compatibility'])) {
            return false;
        }

        $r = 1;
        if (is_array($tables)) {
            // export metadata for each table
            foreach ($tables as $table) {
                $r &= (int) $this->exportConfigurationMetadata($db, $table, $metadataTypes);
            }

            // export metadata for the database
            $r &= (int) $this->exportConfigurationMetadata($db, null, $metadataTypes);
        } else {
            // export metadata for single table
            $r &= (int) $this->exportConfigurationMetadata($db, $tables, $metadataTypes);
        }

        return (bool) $r;
    }

    /**
     * Exports metadata from Configuration Storage
     *
     * @param string      $db            database being exported
     * @param string|null $table         table being exported
     * @param string[]    $metadataTypes types of metadata to export
     */
    private function exportConfigurationMetadata(
        string $db,
        string|null $table,
        array $metadataTypes,
    ): bool {
        $relationParameters = $this->relation->getRelationParameters();
        $relationParams = $relationParameters->toArray();

        if (isset($table)) {
            $types = ['column_info' => 'db_name', 'table_uiprefs' => 'db_name', 'tracking' => 'db_name'];
        } else {
            $types = [
                'bookmark' => 'dbase',
                'relation' => 'master_db',
                'pdf_pages' => 'db_name',
                'savedsearches' => 'db_name',
                'central_columns' => 'db_name',
            ];
        }

        $aliases = [];

        $comment = $this->possibleCRLF() . $this->exportComment();

        if ($table !== null) {
            $comment .= $this->exportComment(
                sprintf(
                    __('Metadata for table %s'),
                    $table,
                ),
            );
        } else {
            $comment .= $this->exportComment(
                sprintf(
                    __('Metadata for database %s'),
                    $db,
                ),
            );
        }

        $comment .= $this->exportComment();

        if (! $this->export->outputHandler($comment)) {
            return false;
        }

        foreach ($types as $type => $dbNameColumn) {
            if (! in_array($type, $metadataTypes) || ! isset($relationParams[$type])) {
                continue;
            }

            $dbi = DatabaseInterface::getInstance();
            // special case, designer pages and their coordinates
            if ($type === 'pdf_pages') {
                if ($relationParameters->pdfFeature === null) {
                    continue;
                }

                $sqlQuery = 'SELECT `page_nr`, `page_descr` FROM '
                    . Util::backquote($relationParameters->pdfFeature->database)
                    . '.' . Util::backquote($relationParameters->pdfFeature->pdfPages)
                    . ' WHERE `db_name` = ' . $dbi->quoteString($db);

                $result = $dbi->fetchResult($sqlQuery, 'page_nr', 'page_descr');

                foreach (array_keys($result) as $page) {
                    // insert row for pdf_page
                    $sqlQueryRow = 'SELECT `db_name`, `page_descr` FROM '
                        . Util::backquote($relationParameters->pdfFeature->database)
                        . '.' . Util::backquote($relationParameters->pdfFeature->pdfPages)
                        . ' WHERE `db_name` = ' . $dbi->quoteString($db)
                        . ' AND `page_nr` = ' . (int) $page;

                    if (
                        ! $this->exportData(
                            $relationParameters->pdfFeature->database->getName(),
                            $relationParameters->pdfFeature->pdfPages->getName(),
                            '',
                            $sqlQueryRow,
                            $aliases,
                        )
                    ) {
                        return false;
                    }

                    $lastPage = "\n"
                        . 'SET @LAST_PAGE = LAST_INSERT_ID();'
                        . "\n";
                    if (! $this->export->outputHandler($lastPage)) {
                        return false;
                    }

                    $sqlQueryCoords = 'SELECT `db_name`, `table_name`, '
                        . "'@LAST_PAGE' AS `pdf_page_number`, `x`, `y` FROM "
                        . Util::backquote($relationParameters->pdfFeature->database)
                        . '.' . Util::backquote($relationParameters->pdfFeature->tableCoords)
                        . " WHERE `pdf_page_number` = '" . $page . "'";

                    $GLOBALS['exporting_metadata'] = true;
                    if (
                        ! $this->exportData(
                            $relationParameters->pdfFeature->database->getName(),
                            $relationParameters->pdfFeature->tableCoords->getName(),
                            '',
                            $sqlQueryCoords,
                            $aliases,
                        )
                    ) {
                        $GLOBALS['exporting_metadata'] = false;

                        return false;
                    }

                    $GLOBALS['exporting_metadata'] = false;
                }

                continue;
            }

            // remove auto_incrementing id field for some tables
            $sqlQuery = match ($type) {
                'bookmark' => 'SELECT `dbase`, `user`, `label`, `query` FROM ',
                'column_info' => 'SELECT `db_name`, `table_name`, `column_name`,'
                    . ' `comment`, `mimetype`, `transformation`,'
                    . ' `transformation_options`, `input_transformation`,'
                    . ' `input_transformation_options` FROM',
                'savedsearches' => 'SELECT `username`, `db_name`, `search_name`, `search_data` FROM',
                default => 'SELECT * FROM ',
            };

            $sqlQuery .= Util::backquote($relationParameters->db)
                . '.' . Util::backquote((string) $relationParams[$type])
                . ' WHERE ' . Util::backquote($dbNameColumn)
                . ' = ' . $dbi->quoteString($db);
            if (isset($table)) {
                $sqlQuery .= ' AND `table_name` = ' . $dbi->quoteString($table);
            }

            if (
                ! $this->exportData(
                    (string) $relationParameters->db,
                    (string) $relationParams[$type],
                    '',
                    $sqlQuery,
                    $aliases,
                )
            ) {
                return false;
            }
        }

        return true;
    }

    /**
     * Returns a stand-in CREATE definition to resolve view dependencies
     *
     * @param string  $db      the database name
     * @param string  $view    the view name
     * @param mixed[] $aliases Aliases of db/table/columns
     *
     * @return string resulting definition
     */
    public function getTableDefStandIn(string $db, string $view, array $aliases = []): string
    {
        $dbAlias = $db;
        $viewAlias = $view;
        $this->initAlias($aliases, $dbAlias, $viewAlias);
        $createQuery = '';
        if (! empty($GLOBALS['sql_drop_table'])) {
            $createQuery .= 'DROP VIEW IF EXISTS '
                . Util::backquote($viewAlias)
                . ';' . "\n";
        }

        $createQuery .= 'CREATE TABLE ';

        if (isset($GLOBALS['sql_if_not_exists']) && $GLOBALS['sql_if_not_exists']) {
            $createQuery .= 'IF NOT EXISTS ';
        }

        $createQuery .= Util::backquote($viewAlias) . ' (' . "\n";
        $tmp = [];
        $columns = DatabaseInterface::getInstance()->getColumnsFull($db, $view);
        foreach ($columns as $columnName => $definition) {
            $colAlias = $columnName;
            if (! empty($aliases[$db]['tables'][$view]['columns'][$colAlias])) {
                $colAlias = $aliases[$db]['tables'][$view]['columns'][$colAlias];
            }

            $tmp[] = Util::backquote($colAlias) . ' ' . $definition['Type'] . "\n";
        }

        return $createQuery . implode(',', $tmp) . ');' . "\n";
    }

    /**
     * Returns CREATE definition that matches $view's structure
     *
     * @param string  $db      the database name
     * @param string  $view    the view name
     * @param mixed[] $aliases Aliases of db/table/columns
     *
     * @return string resulting schema
     */
    private function getTableDefForView(
        string $db,
        string $view,
        array $aliases = [],
    ): string {
        $dbAlias = $db;
        $viewAlias = $view;
        $this->initAlias($aliases, $dbAlias, $viewAlias);
        $createQuery = 'CREATE TABLE';
        if (isset($GLOBALS['sql_if_not_exists'])) {
            $createQuery .= ' IF NOT EXISTS ';
        }

        $createQuery .= Util::backquote($viewAlias) . '(' . "\n";

        $dbi = DatabaseInterface::getInstance();
        $columns = $dbi->getColumns($db, $view, true);

        $firstCol = true;
        foreach ($columns as $column) {
            $colAlias = $column->field;
            if (! empty($aliases[$db]['tables'][$view]['columns'][$colAlias])) {
                $colAlias = $aliases[$db]['tables'][$view]['columns'][$colAlias];
            }

            $extractedColumnspec = Util::extractColumnSpec($column->type);

            if (! $firstCol) {
                $createQuery .= ',' . "\n";
            }

            $createQuery .= '    ' . Util::backquote($colAlias);
            $createQuery .= ' ' . $column->type;
            if ($extractedColumnspec['can_contain_collation'] && ! empty($column->collation)) {
                $createQuery .= ' COLLATE ' . $column->collation;
            }

            if (! $column->isNull) {
                $createQuery .= ' NOT NULL';
            }

            if ($column->default !== null) {
                $createQuery .= ' DEFAULT ' . $dbi->quoteString($column->default);
            } elseif ($column->isNull) {
                $createQuery .= ' DEFAULT NULL';
            }

            if ($column->comment !== '') {
                $createQuery .= ' COMMENT ' . $dbi->quoteString($column->comment);
            }

            $firstCol = false;
        }

        $createQuery .= "\n" . ');' . "\n";

        $compat = $GLOBALS['sql_compatibility'] ?? 'NONE';

        if ($compat === 'MSSQL') {
            return $this->makeCreateTableMSSQLCompatible($createQuery);
        }

        return $createQuery;
    }

    /**
     * Returns $table's CREATE definition
     *
     * @param string  $db                      the database name
     * @param string  $table                   the table name
     * @param bool    $showDates               whether to include creation/
     *                                          update/check dates
     * @param bool    $addSemicolon            whether to add semicolon and
     *                                          end-of-line at the end
     * @param bool    $view                    whether we're handling a view
     * @param bool    $updateIndexesIncrements whether we need to update
     *                                           two global variables
     * @param mixed[] $aliases                 Aliases of db/table/columns
     *
     * @return string resulting schema
     */
    public function getTableDef(
        string $db,
        string $table,
        bool $showDates = false,
        bool $addSemicolon = true,
        bool $view = false,
        bool $updateIndexesIncrements = true,
        array $aliases = [],
    ): string {
        $GLOBALS['sql_drop_table'] ??= null;
        $GLOBALS['sql_constraints'] ??= null;
        $GLOBALS['sql_constraints_query'] ??= null;
        $GLOBALS['sql_indexes'] ??= null;
        $GLOBALS['sql_indexes_query'] ??= null;
        $GLOBALS['sql_auto_increments'] ??= null;
        $GLOBALS['sql_drop_foreign_keys'] ??= null;

        $dbAlias = $db;
        $tableAlias = $table;
        $this->initAlias($aliases, $dbAlias, $tableAlias);

        $compat = $GLOBALS['sql_compatibility'] ?? 'NONE';

        $schemaCreate = $this->getTableStatus($db, $table, $showDates);

        $dbi = DatabaseInterface::getInstance();
        if (! empty($GLOBALS['sql_drop_table']) && $dbi->getTable($db, $table)->isView()) {
            $schemaCreate .= 'DROP VIEW IF EXISTS '
                . Util::backquoteCompat($tableAlias, 'NONE', $this->useSqlBackquotes) . ';'
                . "\n";
        }

        // no need to generate a DROP VIEW here, it was done earlier
        if (! empty($GLOBALS['sql_drop_table']) && ! $dbi->getTable($db, $table)->isView()) {
            $schemaCreate .= 'DROP TABLE IF EXISTS '
                . Util::backquoteCompat($tableAlias, 'NONE', $this->useSqlBackquotes) . ';'
                . "\n";
        }

        // Complete table dump,
        // Whether to quote table and column names or not
        if ($this->useSqlBackquotes) {
            $dbi->query('SET SQL_QUOTE_SHOW_CREATE = 1');
        } else {
            $dbi->query('SET SQL_QUOTE_SHOW_CREATE = 0');
        }

        // I don't see the reason why this unbuffered query could cause problems,
        // because SHOW CREATE TABLE returns only one row, and we free the
        // results below. Nonetheless, we got 2 user reports about this
        // (see bug 1562533) so I removed the unbuffered mode.
        // $result = $dbi->query('SHOW CREATE TABLE ' . backquote($db)
        // . '.' . backquote($table), null, DatabaseInterface::QUERY_UNBUFFERED);
        //
        // Note: SHOW CREATE TABLE, at least in MySQL 5.1.23, does not
        // produce a displayable result for the default value of a BIT
        // column, nor does the mysqldump command. See MySQL bug 35796
        $dbi->tryQuery('USE ' . Util::backquote($db));
        $result = $dbi->tryQuery(
            'SHOW CREATE TABLE ' . Util::backquote($db) . '.'
            . Util::backquote($table),
        );
        // an error can happen, for example the table is crashed
        $tmpError = $dbi->getError();
        if ($tmpError !== '') {
            $message = sprintf(__('Error reading structure for table %s:'), $db . '.' . $table);
            $message .= ' ' . $tmpError;
            if (! defined('TESTSUITE')) {
                trigger_error($message, E_USER_ERROR);
            }

            return $this->exportComment($message);
        }

        // Old mode is stored so it can be restored once exporting is done.
        $oldMode = Context::getMode();

        $warning = '';

        $row = [];
        if ($result !== false) {
            $row = $result->fetchRow();
        }

        if ($row !== []) {
            $createQuery = $row[1];
            unset($row);

            // Convert end of line chars to one that we want (note that MySQL
            // doesn't return query it will accept in all cases)
            if (str_contains($createQuery, "(\r\n ")) {
                $createQuery = str_replace("\r\n", "\n", $createQuery);
            } elseif (str_contains($createQuery, "(\n ")) {
                $createQuery = str_replace("\n", "\n", $createQuery);
            } elseif (str_contains($createQuery, "(\r ")) {
                $createQuery = str_replace("\r", "\n", $createQuery);
            }

            /**
             * Drop database name from VIEW creation.
             *
             * This is a bit tricky, but we need to issue SHOW CREATE TABLE with
             * database name, but we don't want name to show up in CREATE VIEW
             * statement.
             */
            if ($view) {
                //TODO: use parser
                $createQuery = preg_replace(
                    '/' . preg_quote(Util::backquote($db), '/') . '\./',
                    '',
                    $createQuery,
                );
                $parser = new Parser($createQuery);
                /**
                 * `CREATE TABLE` statement.
                 *
                 * @var CreateStatement $statement
                 */
                $statement = $parser->statements[0];

                // exclude definition of current user
                if (
                    Config::getInstance()->settings['Export']['remove_definer_from_definitions']
                    || isset($GLOBALS['sql_view_current_user'])
                ) {
                    $statement->options->remove('DEFINER');
                }

                if (isset($GLOBALS['sql_simple_view_export'])) {
                    $statement->options->remove('SQL SECURITY');
                    $statement->options->remove('INVOKER');
                    $statement->options->remove('ALGORITHM');
                    $statement->options->remove('DEFINER');
                }

                $createQuery = $statement->build();

                // whether to replace existing view or not
                if (isset($GLOBALS['sql_or_replace_view'])) {
                    $createQuery = preg_replace('/^CREATE/', 'CREATE OR REPLACE', $createQuery);
                }
            }

            // Substitute aliases in `CREATE` query.
            $createQuery = $this->replaceWithAliases(null, $createQuery, $aliases, $db, $flag);

            // One warning per view.
            if ($flag && $view) {
                $warning = $this->exportComment()
                    . $this->exportComment(
                        __('It appears your database uses views;'),
                    )
                    . $this->exportComment(
                        __('alias export may not work reliably in all cases.'),
                    )
                    . $this->exportComment();
            }

            // Adding IF NOT EXISTS, if required.
            if (isset($GLOBALS['sql_if_not_exists'])) {
                $createQuery = (string) preg_replace('/^CREATE TABLE/', 'CREATE TABLE IF NOT EXISTS', $createQuery);
            }

            // Making the query MSSQL compatible.
            if ($compat === 'MSSQL') {
                $createQuery = $this->makeCreateTableMSSQLCompatible($createQuery);
            }

            // Views have no constraints, indexes, etc. They do not require any
            // analysis.
            if (! $view) {
                if (! $this->useSqlBackquotes) {
                    // Option "Enclose table and column names with backquotes"
                    // was checked.
                    Context::setMode(Context::getMode() | Context::SQL_MODE_NO_ENCLOSING_QUOTES);
                }

                // Using appropriate quotes.
                if ($compat === 'MSSQL') {
                    Context::setMode(Context::getMode() | Context::SQL_MODE_ANSI_QUOTES);
                }
            }

            /**
             * Parser used for analysis.
             */
            $parser = new Parser($createQuery);

            /**
             * `CREATE TABLE` statement.
             *
             * @var CreateStatement $statement
             */
            $statement = $parser->statements[0];

            if (! empty($statement->entityOptions)) {
                $engine = $statement->entityOptions->has('ENGINE');
            } else {
                $engine = '';
            }

            /* Avoid operation on ARCHIVE tables as those can not be altered */
            if (
                ! empty($statement->fields) && is_array($statement->fields)
                && (empty($engine) || strtoupper($engine) !== 'ARCHIVE')
            ) {

                /**
                 * Fragments containing definition of each constraint.
                 */
                $constraints = [];

                /**
                 * Fragments containing definition of each index.
                 */
                $indexes = [];

                /**
                 * Fragments containing definition of each FULLTEXT index.
                 */
                $indexesFulltext = [];

                /**
                 * Fragments containing definition of each foreign key that will be dropped.
                 */
                $dropped = [];

                /**
                 * Fragment containing definition of the `AUTO_INCREMENT`.
                 */
                $autoIncrement = [];

                // Scanning each field of the `CREATE` statement to fill the arrays
                // above.
                // If the field is used in any of the arrays above, it is removed
                // from the original definition.
                // Also, AUTO_INCREMENT attribute is removed.
                /** @var CreateDefinition $field */
                foreach ($statement->fields as $key => $field) {
                    if ($field->isConstraint) {
                        // Creating the parts that add constraints.
                        $constraints[] = $field->build();
                        unset($statement->fields[$key]);
                    } elseif ($field->key !== null) {
                        // Creating the parts that add indexes (must not be
                        // constraints).
                        if ($field->key->type === 'FULLTEXT KEY') {
                            $indexesFulltext[] = $field->build();
                            unset($statement->fields[$key]);
                        } elseif (empty($GLOBALS['sql_if_not_exists'])) {
                            $indexes[] = str_replace(
                                'COMMENT=\'',
                                'COMMENT \'',
                                $field->build(),
                            );
                            unset($statement->fields[$key]);
                        }
                    }

                    // Creating the parts that drop foreign keys.
                    if ($field->key !== null && $field->key->type === 'FOREIGN KEY' && $field->name !== null) {
                        $dropped[] = 'FOREIGN KEY ' . Context::escape($field->name);
                        unset($statement->fields[$key]);
                    }

                    // Dropping AUTO_INCREMENT.
                    if ($field->options === null) {
                        continue;
                    }

                    if (! $field->options->has('AUTO_INCREMENT') || ! empty($GLOBALS['sql_if_not_exists'])) {
                        continue;
                    }

                    $autoIncrement[] = $field->build();
                    $field->options->remove('AUTO_INCREMENT');
                }

                /**
                 * The header of the `ALTER` statement (`ALTER TABLE tbl`).
                 */
                $alterHeader = 'ALTER TABLE ' . Util::backquoteCompat($tableAlias, $compat, $this->useSqlBackquotes);

                /**
                 * The footer of the `ALTER` statement (usually ';')
                 */
                $alterFooter = ';' . "\n";

                // Generating constraints-related query.
                if ($constraints !== []) {
                    $GLOBALS['sql_constraints_query'] = $alterHeader . "\n" . '  ADD '
                        . implode(',' . "\n" . '  ADD ', $constraints)
                        . $alterFooter;

                    $GLOBALS['sql_constraints'] = $this->generateComment(
                        $GLOBALS['sql_constraints'],
                        __('Constraints for dumped tables'),
                        __('Constraints for table'),
                        $tableAlias,
                        $compat,
                    ) . $GLOBALS['sql_constraints_query'];
                }

                // Generating indexes-related query.
                $GLOBALS['sql_indexes_query'] = '';

                if ($indexes !== []) {
                    $GLOBALS['sql_indexes_query'] .= $alterHeader . "\n" . '  ADD '
                        . implode(',' . "\n" . '  ADD ', $indexes)
                        . $alterFooter;
                }

                if ($indexesFulltext !== []) {
                    // InnoDB supports one FULLTEXT index creation at a time.
                    // So FULLTEXT indexes are created one-by-one after other
                    // indexes where created.
                    $GLOBALS['sql_indexes_query'] .= $alterHeader
                        . ' ADD ' . implode($alterFooter . $alterHeader . ' ADD ', $indexesFulltext)
                        . $alterFooter;
                }

                if ($indexes !== [] || $indexesFulltext !== []) {
                    $GLOBALS['sql_indexes'] = $this->generateComment(
                        $GLOBALS['sql_indexes'],
                        __('Indexes for dumped tables'),
                        __('Indexes for table'),
                        $tableAlias,
                        $compat,
                    ) . $GLOBALS['sql_indexes_query'];
                }

                // Generating drop foreign keys-related query.
                if ($dropped !== []) {
                    $GLOBALS['sql_drop_foreign_keys'] = $alterHeader . "\n" . '  DROP '
                        . implode(',' . "\n" . '  DROP ', $dropped)
                        . $alterFooter;
                }

                // Generating auto-increment-related query.
                if ($autoIncrement !== [] && $updateIndexesIncrements) {
                    $sqlAutoIncrementsQuery = $alterHeader . "\n" . '  MODIFY '
                        . implode(',' . "\n" . '  MODIFY ', $autoIncrement);
                    if (
                        isset($GLOBALS['sql_auto_increment'])
                        && $statement->entityOptions->has('AUTO_INCREMENT') !== false
                        && (! isset($GLOBALS['table_data']) || in_array($table, $GLOBALS['table_data']))
                    ) {
                        $sqlAutoIncrementsQuery .= ', AUTO_INCREMENT='
                            . $statement->entityOptions->has('AUTO_INCREMENT');
                    }

                    $sqlAutoIncrementsQuery .= ';' . "\n";

                    $GLOBALS['sql_auto_increments'] = $this->generateComment(
                        $GLOBALS['sql_auto_increments'],
                        __('AUTO_INCREMENT for dumped tables'),
                        __('AUTO_INCREMENT for table'),
                        $tableAlias,
                        $compat,
                    ) . $sqlAutoIncrementsQuery;
                }

                // Removing the `AUTO_INCREMENT` attribute from the `CREATE TABLE`
                // too.
                if (
                    $statement->entityOptions !== null
                    && (empty($GLOBALS['sql_if_not_exists'])
                    || empty($GLOBALS['sql_auto_increment']))
                ) {
                    $statement->entityOptions->remove('AUTO_INCREMENT');
                }

                // Rebuilding the query.
                $createQuery = $statement->build();
            }

            $schemaCreate .= $createQuery;
        }

        // Restoring old mode.
        Context::setMode($oldMode);

        return $warning . $schemaCreate . ($addSemicolon ? ';' . "\n" : '');
    }

    /**
     * Returns $table's comments, relations etc.
     *
     * @param string  $db         database name
     * @param string  $table      table name
     * @param bool    $doRelation whether to include relation comments
     * @param bool    $doMime     whether to include mime comments
     * @param mixed[] $aliases    Aliases of db/table/columns
     *
     * @return string resulting comments
     */
    private function getTableComments(
        string $db,
        string $table,
        bool $doRelation = false,
        bool $doMime = false,
        array $aliases = [],
    ): string {
        $dbAlias = $db;
        $tableAlias = $table;
        $this->initAlias($aliases, $dbAlias, $tableAlias);

        $relationParameters = $this->relation->getRelationParameters();

        $schemaCreate = '';

        // Check if we can use Relations
        $foreigners = $this->relation->getRelationsAndStatus(
            $doRelation && $relationParameters->relationFeature !== null,
            $db,
            $table,
        );

        $mimeMap = null;
        if ($doMime && $relationParameters->browserTransformationFeature !== null) {
            $mimeMap = $this->transformations->getMime($db, $table, true);
        }

        if ($mimeMap !== null && $mimeMap !== []) {
            $schemaCreate .= $this->possibleCRLF()
                . $this->exportComment()
                . $this->exportComment(
                    __('MEDIA TYPES FOR TABLE') . ' '
                    . Util::backquoteCompat($table, 'NONE', $this->useSqlBackquotes) . ':',
                );
            foreach ($mimeMap as $mimeField => $mime) {
                $schemaCreate .= $this->exportComment(
                    '  '
                    . Util::backquoteCompat($mimeField, 'NONE', $this->useSqlBackquotes),
                )
                . $this->exportComment(
                    '      '
                    . Util::backquoteCompat(
                        $mime['mimetype'],
                        'NONE',
                        $this->useSqlBackquotes,
                    ),
                );
            }

            $schemaCreate .= $this->exportComment();
        }

        if ($foreigners !== []) {
            $schemaCreate .= $this->possibleCRLF()
                . $this->exportComment()
                . $this->exportComment(
                    __('RELATIONSHIPS FOR TABLE') . ' '
                    . Util::backquoteCompat($tableAlias, 'NONE', $this->useSqlBackquotes)
                    . ':',
                );

            foreach ($foreigners as $relField => $rel) {
                if ($relField !== 'foreign_keys_data') {
                    $relFieldAlias = ! empty(
                        $aliases[$db]['tables'][$table]['columns'][$relField]
                    ) ? $aliases[$db]['tables'][$table]['columns'][$relField]
                        : $relField;
                    $schemaCreate .= $this->exportComment(
                        '  '
                        . Util::backquoteCompat(
                            $relFieldAlias,
                            'NONE',
                            $this->useSqlBackquotes,
                        ),
                    )
                    . $this->exportComment(
                        '      '
                        . Util::backquoteCompat(
                            $rel['foreign_table'],
                            'NONE',
                            $this->useSqlBackquotes,
                        )
                        . ' -> '
                        . Util::backquoteCompat(
                            $rel['foreign_field'],
                            'NONE',
                            $this->useSqlBackquotes,
                        ),
                    );
                } else {
                    foreach ($rel as $oneKey) {
                        foreach ($oneKey['index_list'] as $index => $field) {
                            $relFieldAlias = ! empty(
                                $aliases[$db]['tables'][$table]['columns'][$field]
                            ) ? $aliases[$db]['tables'][$table]['columns'][$field]
                                : $field;
                            $schemaCreate .= $this->exportComment(
                                '  '
                                . Util::backquoteCompat(
                                    $relFieldAlias,
                                    'NONE',
                                    $this->useSqlBackquotes,
                                ),
                            )
                            . $this->exportComment(
                                '      '
                                . Util::backquoteCompat(
                                    $oneKey['ref_table_name'],
                                    'NONE',
                                    $this->useSqlBackquotes,
                                )
                                . ' -> '
                                . Util::backquoteCompat(
                                    $oneKey['ref_index_list'][$index],
                                    'NONE',
                                    $this->useSqlBackquotes,
                                ),
                            );
                        }
                    }
                }
            }

            $schemaCreate .= $this->exportComment();
        }

        return $schemaCreate;
    }

    /**
     * Outputs a raw query
     *
     * @param string      $errorUrl the url to go back in case of error
     * @param string|null $db       the database where the query is executed
     * @param string      $sqlQuery the rawquery to output
     */
    public function exportRawQuery(string $errorUrl, string|null $db, string $sqlQuery): bool
    {
        if ($db !== null) {
            DatabaseInterface::getInstance()->selectDb($db);
        }

        return $this->exportData($db ?? '', '', $errorUrl, $sqlQuery);
    }

    /**
     * Outputs table's structure
     *
     * @param string  $db         database name
     * @param string  $table      table name
     * @param string  $exportMode 'create_table', 'triggers', 'create_view', 'stand_in'
     * @param string  $exportType 'server', 'database', 'table'
     * @param bool    $doRelation whether to include relation comments
     * @param bool    $doComments whether to include the pmadb-style column
     *                            comments as comments in the structure; this is
     *                            deprecated but the parameter is left here
     *                            because /export calls exportStructure()
     *                            also for other export types which use this
     *                            parameter
     * @param bool    $doMime     whether to include mime comments
     * @param bool    $dates      whether to include creation/update/check dates
     * @param mixed[] $aliases    Aliases of db/table/columns
     */
    public function exportStructure(
        string $db,
        string $table,
        string $exportMode,
        string $exportType,
        bool $doRelation = false,
        bool $doComments = false,
        bool $doMime = false,
        bool $dates = false,
        array $aliases = [],
    ): bool {
        $dbAlias = $db;
        $tableAlias = $table;
        $this->initAlias($aliases, $dbAlias, $tableAlias);
        $compat = $GLOBALS['sql_compatibility'] ?? 'NONE';

        $formattedTableName = Util::backquoteCompat($tableAlias, $compat, $this->useSqlBackquotes);
        $dump = $this->possibleCRLF()
            . $this->exportComment(str_repeat('-', 56))
            . $this->possibleCRLF()
            . $this->exportComment();

        switch ($exportMode) {
            case 'create_table':
                $dump .= $this->exportComment(
                    __('Table structure for table') . ' ' . $formattedTableName,
                );
                $dump .= $this->exportComment();
                $dump .= $this->getTableDef($db, $table, $dates, true, false, true, $aliases);
                $dump .= $this->getTableComments($db, $table, $doRelation, $doMime, $aliases);
                break;
            case 'triggers':
                $dump = '';
                $delimiter = '$$';
                $triggers = Triggers::getDetails(DatabaseInterface::getInstance(), $db, $table);
                if ($triggers !== []) {
                    $dump .= $this->possibleCRLF()
                    . $this->exportComment()
                    . $this->exportComment(
                        __('Triggers') . ' ' . $formattedTableName,
                    )
                        . $this->exportComment();
                    $usedAlias = false;
                    $triggerQuery = '';
                    foreach ($triggers as $trigger) {
                        if (! empty($GLOBALS['sql_drop_table'])) {
                            $triggerQuery .= $trigger->getDropSql() . ';' . "\n";
                        }

                        $triggerQuery .= 'DELIMITER ' . $delimiter . "\n";
                        $triggerQuery .= $this->replaceWithAliases(
                            $delimiter,
                            $trigger->getCreateSql($delimiter),
                            $aliases,
                            $db,
                            $flag,
                        );
                        if ($flag) {
                            $usedAlias = true;
                        }

                        $triggerQuery .= $delimiter . "\n" . 'DELIMITER ;' . "\n";
                    }

                    // One warning per table.
                    if ($usedAlias) {
                        $dump .= $this->exportComment(
                            __('It appears your table uses triggers;'),
                        )
                        . $this->exportComment(
                            __('alias export may not work reliably in all cases.'),
                        )
                        . $this->exportComment();
                    }

                    $dump .= $triggerQuery;
                }

                break;
            case 'create_view':
                if (empty($GLOBALS['sql_views_as_tables'])) {
                    $dump .= $this->exportComment(
                        __('Structure for view')
                        . ' '
                        . $formattedTableName,
                    )
                    . $this->exportComment();
                    // delete the stand-in table previously created (if any)
                    if ($exportType !== 'table') {
                        $dump .= 'DROP TABLE IF EXISTS '
                            . Util::backquote($tableAlias) . ';' . "\n";
                    }

                    $dump .= $this->getTableDef($db, $table, $dates, true, true, true, $aliases);
                } else {
                    $dump .= $this->exportComment(
                        sprintf(
                            __('Structure for view %s exported as a table'),
                            $formattedTableName,
                        ),
                    )
                    . $this->exportComment();
                    // delete the stand-in table previously created (if any)
                    if ($exportType !== 'table') {
                        $dump .= 'DROP TABLE IF EXISTS '
                        . Util::backquote($tableAlias) . ';' . "\n";
                    }

                    $dump .= $this->getTableDefForView($db, $table, $aliases);
                }

                if (empty($GLOBALS['sql_views_as_tables'])) {
                    // Save views, to be inserted after indexes
                    // in case the view uses USE INDEX syntax
                    $this->sqlViews .= $dump;
                    $dump = '';
                }

                break;
            case 'stand_in':
                $dump .= $this->exportComment(
                    __('Stand-in structure for view') . ' ' . $formattedTableName,
                )
                    . $this->exportComment(
                        __('(See below for the actual view)'),
                    )
                    . $this->exportComment();
                // export a stand-in definition to resolve view dependencies
                $dump .= $this->getTableDefStandIn($db, $table, $aliases);
        }

        // this one is built by getTableDef() to use in table copy/move
        // but not in the case of export
        unset($GLOBALS['sql_constraints_query']);

        return $this->export->outputHandler($dump);
    }

    /**
     * Outputs the content of a table in SQL format
     *
     * @param string  $db       database name
     * @param string  $table    table name
     * @param string  $errorUrl the url to go back in case of error
     * @param string  $sqlQuery SQL query for obtaining data
     * @param mixed[] $aliases  Aliases of db/table/columns
     */
    public function exportData(
        string $db,
        string $table,
        string $errorUrl,
        string $sqlQuery,
        array $aliases = [],
    ): bool {
        $dbi = DatabaseInterface::getInstance();
        // Do not export data for merge tables
        if ($dbi->getTable($db, $table)->isMerge()) {
            return true;
        }

        $dbAlias = $db;
        $tableAlias = $table;
        $this->initAlias($aliases, $dbAlias, $tableAlias);

        $compat = $GLOBALS['sql_compatibility'] ?? 'NONE';

        $formattedTableName = Util::backquoteCompat($tableAlias, $compat, $this->useSqlBackquotes);

        // Do not export data for a VIEW, unless asked to export the view as a table
        // (For a VIEW, this is called only when exporting a single VIEW)
        if ($dbi->getTable($db, $table)->isView() && empty($GLOBALS['sql_views_as_tables'])) {
            $head = $this->possibleCRLF()
                . $this->exportComment()
                . $this->exportComment('VIEW ' . $formattedTableName)
                . $this->exportComment(__('Data:') . ' ' . __('None'))
                . $this->exportComment()
                . $this->possibleCRLF();

            return $this->export->outputHandler($head);
        }

        $result = $dbi->tryQuery($sqlQuery, ConnectionType::User, DatabaseInterface::QUERY_UNBUFFERED);
        // a possible error: the table has crashed
        $tmpError = $dbi->getError();
        if ($tmpError !== '') {
            $message = sprintf(__('Error reading data for table %s:'), $db . '.' . $table);
            $message .= ' ' . $tmpError;
            if (! defined('TESTSUITE')) {
                trigger_error($message, E_USER_ERROR);
            }

            return $this->export->outputHandler(
                $this->exportComment($message),
            );
        }

        if ($result === false) {
            return true;
        }

        $fieldsCnt = $result->numFields();

        // Get field information
        $fieldsMeta = $dbi->getFieldsMeta($result);

        $fieldSet = [];
        /** @infection-ignore-all */
        for ($j = 0; $j < $fieldsCnt; $j++) {
            $colAs = $fieldsMeta[$j]->name;
            if (! empty($aliases[$db]['tables'][$table]['columns'][$colAs])) {
                $colAs = $aliases[$db]['tables'][$table]['columns'][$colAs];
            }

            $fieldSet[$j] = Util::backquoteCompat($colAs, $compat, $this->useSqlBackquotes);
        }

        if (isset($GLOBALS['sql_type']) && $GLOBALS['sql_type'] === 'UPDATE') {
            // update
            $schemaInsert = 'UPDATE ';
            if (isset($GLOBALS['sql_ignore'])) {
                $schemaInsert .= 'IGNORE ';
            }

            // avoid EOL blank
            $schemaInsert .= Util::backquoteCompat($tableAlias, $compat, $this->useSqlBackquotes) . ' SET';
        } else {
            // insert or replace
            if (isset($GLOBALS['sql_type']) && $GLOBALS['sql_type'] === 'REPLACE') {
                $sqlCommand = 'REPLACE';
            } else {
                $sqlCommand = 'INSERT';
            }

            // delayed inserts?
            if (isset($GLOBALS['sql_delayed'])) {
                $insertDelayed = ' DELAYED';
            } else {
                $insertDelayed = '';
            }

            // insert ignore?
            if (isset($GLOBALS['sql_type'], $GLOBALS['sql_ignore']) && $GLOBALS['sql_type'] === 'INSERT') {
                $insertDelayed .= ' IGNORE';
            }

            //truncate table before insert
            if (isset($GLOBALS['sql_truncate']) && $GLOBALS['sql_truncate'] && $sqlCommand === 'INSERT') {
                $truncate = 'TRUNCATE TABLE '
                    . Util::backquoteCompat($tableAlias, $compat, $this->useSqlBackquotes) . ';';
                $truncatehead = $this->possibleCRLF()
                    . $this->exportComment()
                    . $this->exportComment(
                        __('Truncate table before insert') . ' '
                        . $formattedTableName,
                    )
                    . $this->exportComment()
                    . "\n";
                $this->export->outputHandler($truncatehead);
                $this->export->outputHandler($truncate);
            }

            // scheme for inserting fields
            if ($GLOBALS['sql_insert_syntax'] === 'complete' || $GLOBALS['sql_insert_syntax'] === 'both') {
                $fields = implode(', ', $fieldSet);
                $schemaInsert = $sqlCommand . $insertDelayed . ' INTO '
                    . Util::backquoteCompat($tableAlias, $compat, $this->useSqlBackquotes)
                    . ' (' . $fields . ') VALUES'; // avoid EOL blank
            } else {
                $schemaInsert = $sqlCommand . $insertDelayed . ' INTO '
                    . Util::backquoteCompat($tableAlias, $compat, $this->useSqlBackquotes)
                    . ' VALUES';
            }
        }

        //\x08\\x09, not required
        $currentRow = 0;
        $querySize = 0;
        if (
            ($GLOBALS['sql_insert_syntax'] === 'extended'
            || $GLOBALS['sql_insert_syntax'] === 'both')
            && (! isset($GLOBALS['sql_type'])
            || $GLOBALS['sql_type'] !== 'UPDATE')
        ) {
            $separator = ',';
            $schemaInsert .= "\n";
        } else {
            $separator = ';';
        }

        while ($row = $result->fetchRow()) {
            if ($currentRow === 0) {
                $head = $this->possibleCRLF()
                    . $this->exportComment()
                    . $this->exportComment(
                        __('Dumping data for table') . ' '
                        . $formattedTableName,
                    )
                    . $this->exportComment()
                    . "\n";
                if (! $this->export->outputHandler($head)) {
                    return false;
                }
            }

            // We need to SET IDENTITY_INSERT ON for MSSQL
            if (
                $currentRow === 0
                && isset($GLOBALS['sql_compatibility'])
                && $GLOBALS['sql_compatibility'] === 'MSSQL'
            ) {
                if (
                    ! $this->export->outputHandler(
                        'SET IDENTITY_INSERT '
                        . Util::backquoteCompat(
                            $tableAlias,
                            $compat,
                            $this->useSqlBackquotes,
                        )
                        . ' ON ;' . "\n",
                    )
                ) {
                    return false;
                }
            }

            $currentRow++;
            $values = [];
            foreach ($fieldsMeta as $j => $metaInfo) {
                // NULL
                if ($row[$j] === null) {
                    $values[] = 'NULL';
                } elseif (
                    $metaInfo->isNumeric
                ) {
                    // a number
                    $values[] = $row[$j];
                } elseif ($metaInfo->isBinary && isset($GLOBALS['sql_hex_for_binary'])) {
                    // a true BLOB
                    // - mysqldump only generates hex data when the --hex-blob
                    //   option is used, for fields having the binary attribute
                    //   no hex is generated
                    // - a TEXT field returns type blob but a real blob
                    //   returns also the 'binary' flag

                    // empty blobs need to be different, but '0' is also empty
                    // :-(
                    if (empty($row[$j]) && $row[$j] != '0') {
                        $values[] = '\'\'';
                    } else {
                        $values[] = '0x' . bin2hex($row[$j]);
                    }
                } elseif ($metaInfo->isMappedTypeBit) {
                    // detection of 'bit' works only on mysqli extension
                    $values[] = "b'" . Util::printableBitValue((int) $row[$j], $metaInfo->length) . "'";
                } elseif ($metaInfo->isMappedTypeGeometry) {
                    // export GIS types as hex
                    $values[] = '0x' . bin2hex($row[$j]);
                } elseif (! empty($GLOBALS['exporting_metadata']) && $row[$j] === '@LAST_PAGE') {
                    $values[] = '@LAST_PAGE';
                } elseif ($row[$j] === '') {
                    $values[] = "''";
                } else {
                    // something else -> treat as a string
                    $values[] = $dbi->quoteString($row[$j]);
                }
            }

            // should we make update?
            if (isset($GLOBALS['sql_type']) && $GLOBALS['sql_type'] === 'UPDATE') {
                $insertLine = $schemaInsert;
                /** @infection-ignore-all */
                for ($i = 0; $i < $fieldsCnt; $i++) {
                    if ($i === 0) {
                        $insertLine .= ' ';
                    }

                    if ($i > 0) {
                        // avoid EOL blank
                        $insertLine .= ',';
                    }

                    $insertLine .= $fieldSet[$i] . ' = ' . $values[$i];
                }

                $insertLine .= ' WHERE ' . (new UniqueCondition($fieldsMeta, $row))->getWhereClause();
            } elseif ($GLOBALS['sql_insert_syntax'] === 'extended' || $GLOBALS['sql_insert_syntax'] === 'both') {
                // Extended inserts case
                if ($currentRow === 1) {
                    $insertLine = $schemaInsert . '('
                        . implode(', ', $values) . ')';
                } else {
                    $insertLine = '(' . implode(', ', $values) . ')';
                    $insertLineSize = mb_strlen($insertLine);
                    $sqlMaxSize = $GLOBALS['sql_max_query_size'];
                    if ($sqlMaxSize > 0 && $querySize + $insertLineSize > $sqlMaxSize) {
                        if (! $this->export->outputHandler(';' . "\n")) {
                            return false;
                        }

                        $querySize = 0;
                        $currentRow = 1;
                        $insertLine = $schemaInsert . $insertLine;
                    }
                }

                $querySize += mb_strlen($insertLine);
            } else {
                // Other inserts case
                $insertLine = $schemaInsert . '(' . implode(', ', $values) . ')';
            }

            if (! $this->export->outputHandler(($currentRow === 1 ? '' : $separator . "\n") . $insertLine)) {
                return false;
            }
        }

        if ($currentRow > 0) {
            if (! $this->export->outputHandler(';' . "\n")) {
                return false;
            }
        }

        // We need to SET IDENTITY_INSERT OFF for MSSQL
        if (
            isset($GLOBALS['sql_compatibility'])
            && $GLOBALS['sql_compatibility'] === 'MSSQL'
            && $currentRow > 0
        ) {
            $outputSucceeded = $this->export->outputHandler(
                "\n" . 'SET IDENTITY_INSERT '
                . Util::backquoteCompat(
                    $tableAlias,
                    $compat,
                    $this->useSqlBackquotes,
                )
                . ' OFF;' . "\n",
            );
            if (! $outputSucceeded) {
                return false;
            }
        }

        return true;
    }

    /**
     * Make a create table statement compatible with MSSQL
     *
     * @param string $createQuery MySQL create table statement
     *
     * @return string MSSQL compatible create table statement
     */
    private function makeCreateTableMSSQLCompatible(string $createQuery): string
    {
        // In MSSQL
        // 1. No 'IF NOT EXISTS' in CREATE TABLE
        // 2. DATE field doesn't exists, we will use DATETIME instead
        // 3. UNSIGNED attribute doesn't exist
        // 4. No length on INT, TINYINT, SMALLINT, BIGINT and no precision on
        //    FLOAT fields
        // 5. No KEY and INDEX inside CREATE TABLE
        // 6. DOUBLE field doesn't exists, we will use FLOAT instead

        $createQuery = (string) preg_replace('/^CREATE TABLE IF NOT EXISTS/', 'CREATE TABLE', $createQuery);
        // first we need  to replace all lines ended with '" DATE ...,\n'
        // last preg_replace preserve us from situation with date text
        // inside DEFAULT field value
        $createQuery = (string) preg_replace(
            "/\" date DEFAULT NULL(,)?\n/",
            '" datetime DEFAULT NULL$1' . "\n",
            $createQuery,
        );
        $createQuery = (string) preg_replace("/\" date NOT NULL(,)?\n/", '" datetime NOT NULL$1' . "\n", $createQuery);
        $createQuery = (string) preg_replace(
            '/" date NOT NULL DEFAULT \'([^\'])/',
            '" datetime NOT NULL DEFAULT \'$1',
            $createQuery,
        );

        // next we need to replace all lines ended with ') UNSIGNED ...,'
        // last preg_replace preserve us from situation with unsigned text
        // inside DEFAULT field value
        $createQuery = (string) preg_replace("/\) unsigned NOT NULL(,)?\n/", ') NOT NULL$1' . "\n", $createQuery);
        $createQuery = (string) preg_replace(
            "/\) unsigned DEFAULT NULL(,)?\n/",
            ') DEFAULT NULL$1' . "\n",
            $createQuery,
        );
        $createQuery = (string) preg_replace(
            '/\) unsigned NOT NULL DEFAULT \'([^\'])/',
            ') NOT NULL DEFAULT \'$1',
            $createQuery,
        );

        // we need to replace all lines ended with
        // '" INT|TINYINT([0-9]{1,}) ...,' last preg_replace preserve us
        // from situation with int([0-9]{1,}) text inside DEFAULT field
        // value
        $createQuery = (string) preg_replace(
            '/" (int|tinyint|smallint|bigint)\([0-9]+\) DEFAULT NULL(,)?\n/',
            '" $1 DEFAULT NULL$2' . "\n",
            $createQuery,
        );
        $createQuery = (string) preg_replace(
            '/" (int|tinyint|smallint|bigint)\([0-9]+\) NOT NULL(,)?\n/',
            '" $1 NOT NULL$2' . "\n",
            $createQuery,
        );
        $createQuery = (string) preg_replace(
            '/" (int|tinyint|smallint|bigint)\([0-9]+\) NOT NULL DEFAULT \'([^\'])/',
            '" $1 NOT NULL DEFAULT \'$2',
            $createQuery,
        );

        // we need to replace all lines ended with
        // '" FLOAT|DOUBLE([0-9,]{1,}) ...,'
        // last preg_replace preserve us from situation with
        // float([0-9,]{1,}) text inside DEFAULT field value
        $createQuery = (string) preg_replace(
            '/" (float|double)(\([0-9]+,[0-9,]+\))? DEFAULT NULL(,)?\n/',
            '" float DEFAULT NULL$3' . "\n",
            $createQuery,
        );
        $createQuery = (string) preg_replace(
            '/" (float|double)(\([0-9,]+,[0-9,]+\))? NOT NULL(,)?\n/',
            '" float NOT NULL$3' . "\n",
            $createQuery,
        );

        return (string) preg_replace(
            '/" (float|double)(\([0-9,]+,[0-9,]+\))? NOT NULL DEFAULT \'([^\'])/',
            '" float NOT NULL DEFAULT \'$3',
            $createQuery,
        );

        // @todo remove indexes from CREATE TABLE
    }

    /**
     * replaces db/table/column names with their aliases
     *
     * @param string|null $delimiter The delimiter for the parser (";" or "$$")
     * @param string      $sqlQuery  SQL query in which aliases are to be substituted
     * @param mixed[]     $aliases   Alias information for db/table/column
     * @param string      $db        the database name
     * @param bool|null   $flag      the flag denoting whether any replacement was done
     *
     * @return string query replaced with aliases
     */
    public function replaceWithAliases(
        string|null $delimiter,
        string $sqlQuery,
        array $aliases,
        string $db,
        bool|null &$flag = null,
    ): string {
        $flag = false;

        /**
         * The parser of this query.
         */
        $parser = new Parser(empty($delimiter) ? $sqlQuery : 'DELIMITER ' . $delimiter . "\n" . $sqlQuery);

        if (empty($parser->statements[0])) {
            return $sqlQuery;
        }

        /**
         * The statement that represents the query.
         *
         * @var CreateStatement $statement
         */
        $statement = $parser->statements[0];

        /**
         * Old database name.
         */
        $oldDatabase = $db;

        // Replacing aliases in `CREATE TABLE` statement.
        if ($statement->options->has('TABLE')) {
            // Extracting the name of the old database and table from the
            // statement to make sure the parameters are correct.
            if (! empty($statement->name->database)) {
                $oldDatabase = $statement->name->database;
            }

            /**
             * Old table name.
             */
            $oldTable = $statement->name->table;

            // Finding the aliased database name.
            // The database might be empty so we have to add a few checks.
            $newDatabase = null;
            if (! empty($statement->name->database)) {
                $newDatabase = $statement->name->database;
                if (! empty($aliases[$oldDatabase]['alias'])) {
                    $newDatabase = $aliases[$oldDatabase]['alias'];
                }
            }

            // Finding the aliases table name.
            $newTable = $oldTable;
            if (! empty($aliases[$oldDatabase]['tables'][$oldTable]['alias'])) {
                $newTable = $aliases[$oldDatabase]['tables'][$oldTable]['alias'];
            }

            // Replacing new values.
            if ($statement->name->database !== $newDatabase || $statement->name->table !== $newTable) {
                $statement->name->database = $newDatabase;
                $statement->name->table = $newTable;
                $statement->name->expr = ''; // Force rebuild.
                $flag = true;
            }

            /** @var CreateDefinition[] $fields */
            $fields = $statement->fields;
            foreach ($fields as $field) {
                // Column name.
                if (
                    $field->type !== null
                    && ! empty($aliases[$oldDatabase]['tables'][$oldTable]['columns'][$field->name])
                ) {
                    $field->name = $aliases[$oldDatabase]['tables'][$oldTable]['columns'][$field->name];
                    $flag = true;
                }

                // Key's columns.
                if ($field->key !== null) {
                    foreach ($field->key->columns as $key => $column) {
                        if (! isset($column['name'])) {
                            // In case the column has no name field
                            continue;
                        }

                        if (empty($aliases[$oldDatabase]['tables'][$oldTable]['columns'][$column['name']])) {
                            continue;
                        }

                        $columnAliases = $aliases[$oldDatabase]['tables'][$oldTable]['columns'];
                        $field->key->columns[$key]['name'] = $columnAliases[$column['name']];
                        $flag = true;
                    }
                }

                // References.
                if ($field->references === null) {
                    continue;
                }

                $refTable = $field->references->table->table;
                // Replacing table.
                if (! empty($aliases[$oldDatabase]['tables'][$refTable]['alias'])) {
                    $field->references->table->table = $aliases[$oldDatabase]['tables'][$refTable]['alias'];
                    $field->references->table->expr = '';
                    $flag = true;
                }

                // Replacing column names.
                foreach ($field->references->columns as $key => $column) {
                    if (empty($aliases[$oldDatabase]['tables'][$refTable]['columns'][$column])) {
                        continue;
                    }

                    $field->references->columns[$key] = $aliases[$oldDatabase]['tables'][$refTable]['columns'][$column];
                    $flag = true;
                }
            }
        } elseif ($statement->options->has('TRIGGER')) {
            // Extracting the name of the old database and table from the
            // statement to make sure the parameters are correct.
            if (! empty($statement->table->database)) {
                $oldDatabase = $statement->table->database;
            }

            /**
             * Old table name.
             */
            $oldTable = $statement->table->table;

            if (! empty($aliases[$oldDatabase]['tables'][$oldTable]['alias'])) {
                $statement->table->table = $aliases[$oldDatabase]['tables'][$oldTable]['alias'];
                $statement->table->expr = ''; // Force rebuild.
                $flag = true;
            }
        }

        if (
            $statement->options->has('TRIGGER')
            || $statement->options->has('PROCEDURE')
            || $statement->options->has('FUNCTION')
            || $statement->options->has('VIEW')
        ) {
            // Replacing the body.
            foreach ($statement->body as $token) {
                // Replacing only symbols (that are not variables) and unknown identifiers.
                $isSymbol = $token->type === TokenType::Symbol;
                $isKeyword = $token->type === TokenType::Keyword;
                $isNone = $token->type === TokenType::None;
                $replaceToken = $isSymbol && ($token->flags & Token::FLAG_SYMBOL_VARIABLE) === 0
                    || $isKeyword && ($token->flags & Token::FLAG_KEYWORD_RESERVED) === 0
                    || $isNone;
                if (! $replaceToken) {
                    continue;
                }

                $alias = $this->getAlias($aliases, $token->value);
                if ($alias === '') {
                    continue;
                }

                // Replacing the token.
                $token->token = Context::escape($alias);
                $flag = true;
            }
        }

        return $statement->build();
    }

    /**
     * Generate comment
     *
     * @param string|null $sqlStatement SQL statement
     * @param string      $comment1     Comment for dumped table
     * @param string      $comment2     Comment for current table
     * @param string      $tableAlias   Table alias
     * @param string      $compat       Compatibility mode
     */
    protected function generateComment(
        string|null $sqlStatement,
        string $comment1,
        string $comment2,
        string $tableAlias,
        string $compat,
    ): string {
        if ($sqlStatement === null) {
            if (isset($GLOBALS['no_constraints_comments'])) {
                $sqlStatement = '';
            } else {
                $sqlStatement = "\n"
                    . $this->exportComment()
                    . $this->exportComment($comment1)
                    . $this->exportComment();
            }
        }

        // comments for current table
        if (! isset($GLOBALS['no_constraints_comments'])) {
            $sqlStatement .= "\n"
                . $this->exportComment()
                . $this->exportComment(
                    $comment2 . ' ' . Util::backquoteCompat(
                        $tableAlias,
                        $compat,
                        $this->useSqlBackquotes,
                    ),
                )
                . $this->exportComment();
        }

        return $sqlStatement;
    }

    private function getTableStatus(string $db, string $table, bool $showDates): string
    {
        $newCrlf = "\n";
        $schemaCreate = '';

        $dbi = DatabaseInterface::getInstance();
        $result = $dbi->tryQuery(
            'SHOW TABLE STATUS FROM ' . Util::backquote($db)
            . ' WHERE Name = ' . $dbi->quoteString($table),
        );
        if ($result !== false && $result->numRows() > 0) {
            $tmpres = $result->fetchAssoc();

            if ($showDates && ! empty($tmpres['Create_time'])) {
                $schemaCreate .= $this->exportComment(
                    __('Creation:') . ' '
                    . Util::localisedDate(
                        strtotime($tmpres['Create_time']),
                    ),
                );
                $newCrlf = $this->exportComment() . "\n";
            }

            if ($showDates && ! empty($tmpres['Update_time'])) {
                $schemaCreate .= $this->exportComment(
                    __('Last update:') . ' '
                    . Util::localisedDate(
                        strtotime($tmpres['Update_time']),
                    ),
                );
                $newCrlf = $this->exportComment() . "\n";
            }

            if ($showDates && ! empty($tmpres['Check_time'])) {
                $schemaCreate .= $this->exportComment(
                    __('Last check:') . ' '
                    . Util::localisedDate(
                        strtotime($tmpres['Check_time']),
                    ),
                );
                $newCrlf = $this->exportComment() . "\n";
            }
        }

        return $schemaCreate . $newCrlf;
    }

    /** @param string[] $compats */
    private function addCompatOptions(array $compats, OptionsPropertyMainGroup $generalOptions): void
    {
        $values = [];
        foreach ($compats as $val) {
            $values[$val] = $val;
        }

        $leaf = new SelectPropertyItem(
            'compatibility',
            __(
                'Database system or older MySQL server to maximize output compatibility with:',
            ),
        );
        $leaf->setValues($values);
        $leaf->setDoc(
            ['manual_MySQL_Database_Administration', 'Server_SQL_mode'],
        );
        $generalOptions->addProperty($leaf);
    }
}