Convert charset to utf8mb4 to resolve invalid character issues

app/migrations/Version20211020114811.php

@@ -0,0 +1,107 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Mautic\Migrations;
+
+use Doctrine\DBAL\Exception;
+use Doctrine\DBAL\Schema\Schema;
+use Mautic\CoreBundle\Doctrine\AbstractMauticMigration;
+
+final class Version20211020114811 extends AbstractMauticMigration
+{
+    public function up(Schema $schema): void
+    {
+        $this->addSql('SET FOREIGN_KEY_CHECKS=0;');
+
+        /*
+         * The index key prefix length limit is 3072 bytes for InnoDB tables.
+         * In utf8mb4, 1 char uses 4 bytes
+         * So if we are creating multiple columns index for 4 columns of varchar(255) then it will take 255*4*4 = 4080.
+         * 4080 bytes is more than max allowed limit 3072 bytes.
+         * So it was not allowing to convert charset for particular tables and was showing error
+         * "Specified key was too long; max key length is 3072 bytes"
+         */
+
+        $dropIndexQuery = 'DROP INDEX %s on %s';
+
+        $this->addSql(
+            sprintf(
+                $dropIndexQuery,
+                $this->prefix.'company_match',
+                $this->getPrefixedTableName('companies')
+            )
+        );
+        $this->addSql(
+            sprintf(
+                'CREATE INDEX %s on %s(`companyname`(191),`companycity`(191),`companycountry`(191),`companystate`(191))',
+                $this->prefix.'company_match',
+                $this->getPrefixedTableName('companies')
+            )
+        );
+
+        $this->addSql(
+            sprintf(
+                $dropIndexQuery,
+                $this->prefix.'integration_object',
+                $this->getPrefixedTableName('sync_object_mapping')
+            )
+        );
+        $this->addSql(
+            sprintf(
+                'CREATE INDEX %s on %s(`integration`(191),`integration_object_name`(191),`integration_object_id`(191), `integration_reference_id`(191))',
+                $this->prefix.'integration_object',
+                $this->getPrefixedTableName('sync_object_mapping')
+            )
+        );
+
+        $this->addSql(
+            sprintf(
+                $dropIndexQuery,
+                $this->prefix.'integration_reference',
+                $this->getPrefixedTableName('sync_object_mapping')
+            )
+        );
+        $this->addSql(
+            sprintf(
+                'CREATE INDEX %s on %s(`integration`(191),`integration_object_name`(191), `integration_reference_id`(191), `integration_object_id`(191))',
+                $this->prefix.'integration_reference',
+                $this->getPrefixedTableName('sync_object_mapping')
+            )
+        );
+
+        $tables = $this->getTables();
+        foreach ($tables as $table) {
+            $tableName = $table['TABLE_NAME'];
+            $this->addSql(
+                sprintf(
+                    'ALTER TABLE %s CONVERT TO CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci;',
+                    $tableName)
+            );
+        }
+        $this->addSql('SET FOREIGN_KEY_CHECKS=1;');
+    }
+
+    /**
+     * @return mixed[]
+     *
+     * @throws Exception
+     */
+    private function getTables(): array
+    {
+        $stmt = $this->connection->executeQuery(
+            "SELECT TABLE_NAME, TABLE_COLLATION FROM information_schema.TABLES AS T
+            INNER JOIN information_schema.COLLATION_CHARACTER_SET_APPLICABILITY AS C
+            ON (C.collation_name = T.table_collation) WHERE
+            T.TABLE_SCHEMA = '{$this->connection->getDatabase()}' AND
+            (C.CHARACTER_SET_NAME != 'utf8mb4' OR C.COLLATION_NAME != 'utf8mb4_unicode_ci')"
+        );
+
+        return $stmt->fetchAllAssociative();
+    }
+
+    private function getPrefixedTableName(string $tableName): string
+    {
+        return $this->prefix.$tableName;
+    }
+}