Exporting results of SQL query causes "bad parameters" error when a database is not selected first

[jormaster3k]

Describe the bug

Exporting results of SQL query causes "bad parameters" error when a database is not selected first

To Reproduce

Steps to reproduce the behavior:

1. Login to PHPMyAdmin
2. Click on "SQL" tab
3. Enter a valid query, e.g. "select 1 from dual;"
4. Click Go
5. Click Export
6. Use default options and click "Go"
7. Receive error "Bad parameters!"

Expected behavior

Expect to generate a file containing query results

Screenshots

Server configuration

• Operating system: Ubuntu 14.04
• Web server: Apache 2.4
• Database version: 5.7.23-0ubuntu0.16.04.1-log
• PHP version: 5.5.9-1ubuntu4.25
• phpMyAdmin version: 4.8.3

Client configuration

• Browser: Chrome
• Operating system: Windows 10

Additional context

The "bad parameters" message is generated on line 292 in export.php:

phpmyadmin/export.php

Lines 274 to 293 in 2fc8bb1

	// Generate error url and check for needed variables
	if ($export_type == 'server') {
	$err_url = 'server_export.php' . Url::getCommon();
	} elseif ($export_type == 'database' && strlen($db) > 0) {
	$err_url = 'db_export.php' . Url::getCommon(['db' => $db]);
	// Check if we have something to export
	if (isset($table_select)) {
	$tables = $table_select;
	} else {
	$tables = [];
	}
	} elseif ($export_type == 'table' && strlen($db) > 0 && strlen($table) > 0) {
	$err_url = 'tbl_export.php' . Url::getCommon(
	[
	'db' => $db, 'table' => $table
	]
	);
	} else {
	Core::fatalError(__('Bad parameters!'));
	}

The problem appears to be the fact that since we ran the query without selecting a database yet, the $db parameter is not present in the POST request, triggering the fatal error.

[Gaurav-Punjabi]

So what should we do to fix this issue?
Should we display a warning to the user that no DB is selected?

[williamdes]

Successfully reproduced on demo servers (root, no password)

• 5.0.0-dev
• 4.8.x

@Gaurav-Punjabi The data should export as expected ;)
No need to select a database (IMO)

[Thedijje]

So what should we do to fix this issue?
Should we display a warning to the user that no DB is selected?

@Gaurav-Punjabi We should debug if the database is selected by the export query, as per my experience, I tried selecting database many times but on the error, I kept finding out that database gets unselect.

[computerManiac]

This piece of code makes sure that a table is always selected when we export,

phpmyadmin/libraries/classes/Display/Results.php

Lines 5229 to 5235 in 0a0bc2c

	if (empty($_url_params['table']) && ! empty($_url_params['db'])) {
	$_url_params['table'] = $GLOBALS['dbi']->fetchValue("SHOW TABLES");
	/* No result (probably no database selected) */
	if ($_url_params['table'] === false) {
	unset($_url_params['table']);
	}
	}

But since we don't have any database selected it fails. Should we explicitly set the database and table to a string 'none' so that export doesn't fail ?

[nmilo]

Couldn't reproduce this on latest version, should this be closed?

[bahl24]

@williamdes I agree with @nmilo

[svaningelgem]

I could reproduce this on the current 4.8 version:

Reproduction steps:

1. go to the url & log on
2. click on the SQL tab on top (don't select anything else)
3. enter the query: "select * from acid.authors;" (hopefully it still exists when you check it ;-))
4. run it
5. it will show the table with the entries
6. click on the "export" tab on top.
7. here it says "exporting from table authors" >> So it does actually know what database and everything the query is supposed to be run in.
8. doesn't matter which type of export, so I just clicked the button.
9. "Bad parameters"

[tlshifat]

Successfully reproduced on demo servers (root, no password)

* [`5.0.0-dev`](https://demo.phpmyadmin.net/master-config/)

* [`4.8.x`](https://demo.phpmyadmin.net/QA_4_8/)

@Gaurav-Punjabi The data should export as expected ;)
No need to select a database (IMO)

if database is not selected then we have to take database name from sql_query . right?

[tlshifat]

@williamdes if database is not selected then we have to take database name from sql_query . right?

[williamdes]

@shifatbuet Would make sense, but what if the query uses a join ?
or uses multiple tables in the FROM clause ?

[tlshifat]

@williamdes I was thinking about this :

• explode sql query(select * from a join a b c d e f) to array using space.
• find the position of 'FROM' or 'from' ex: 3
• get number 4 postions value.
• if contains dot (.) explode it again otherwise it is the db.
• if doesn't contain dot (.) finally exploded array[0] is db.

[williamdes]

@shifatbuet You should not do that, we have https://github.com/phpmyadmin/sql-parser to do the work :)

[tlshifat]

@williamdes okay. may be i have to do it in URL . like CommonParams.set('db', data.params.db);.

I am really confused , how to do it from php code and also refresh so that url shows db= something. Can you help me a little bit?

[williamdes]

@shifatbuet I think we need a different approach: disable the db verification
Is it possible: maybe it is so hard to do it in the code base of export page that we can not do it.

beacause the query of this issue is select 1 from dual; obviously has no real database