SQLite plugin not working on SQLite 3.34.1

[sejas]

What happened?

When importing a site with this plugin and an existing database on my server with SQLite 3.34.1 I got a fatal error:

[18-Sep-2025 17:46:32 UTC] PHP Fatal error:  Uncaught PDOException: SQLSTATE[HY000]: General error: 11 malformed database schema (_wp_sqlite_mysql_information_schema_schemata) - near "STRICT": syntax error in /srv/htdocs/wp-content/mu-plugins/sqlite-database-integration/wp-includes/sqlite/class-wp-sqlite-translator.php:401
Stack trace:
#0 /srv/htdocs/wp-content/mu-plugins/sqlite-database-integration/wp-includes/sqlite/class-wp-sqlite-translator.php(401): PDO->query('CREATE TABLE IF...')
#1 /srv/htdocs/wp-content/mu-plugins/sqlite-database-integration/wp-includes/sqlite/class-wp-sqlite-db.php(348): WP_SQLite_Translator->__construct(Object(PDO))
#2 /srv/htdocs/__wp__/wp-includes/class-wpdb.php(773): WP_SQLite_DB->db_connect()
#3 /srv/htdocs/wp-content/mu-plugins/sqlite-database-integration/wp-includes/sqlite/class-wp-sqlite-db.php(55): wpdb->__construct('', Object(SensitiveParameterValue), '151359310', '')
#4 /srv/htdocs/wp-content/mu-plugins/sqlite-database-integration/wp-includes/sqlite/db.php(84): WP_SQLite_DB->__construct('151359310')
#5 /srv/htdocs/wp-content/db.php(37): require_once('/srv/htdocs/wp-...')
#6 /srv/htdocs/__wp__/wp-includes/load.php(708): require_once('/srv/htdocs/wp-...')
#7 /srv/htdocs/__wp__/wp-settings.php(134): require_wp_db()
#8 /srv/htdocs/wp-config.php(105): require_once('/srv/htdocs/__w...')
#9 /srv/htdocs/__wp__/wp-load.php(55): require_once('/srv/htdocs/wp-...')
#10 /srv/htdocs/__wp__/wp-blog-header.php(13): require_once('/srv/htdocs/__w...')
#11 /srv/htdocs/__wp__/index.php(17): require('/srv/htdocs/__w...')
#12 {main}
  thrown in /srv/htdocs/wp-content/mu-plugins/sqlite-database-integration/wp-includes/sqlite/class-wp-sqlite-translator.php on line 401

What would I expect?

It would be great if the plugin is compatible with this SQLite version, or it's able to load the SQLite binary version needed, or if at least it fails gracefully explaining why it cannot use these versions.

[mati75]

For me plugin works with this sqlite3 version.

Here your database file is malformed. You need fix it first.

[JanJakes]

@sejas Thanks for reporting this!

The SQLite docs mention a trick for Accessing STRICT tables in earlier versions of SQLite. I will give it a try and would consider emitting a PHP warning when the SQLite version is below 3.37.0. Would that be enough for your use case? It would likely enable both read and write on older SQLite versions, at the risk of possibly more differences in MySQL vs. SQLite behavior when writing data.

[JanJakes]

@sejas Alternatively to the warning, I wonder if it would make sense to enable configuring this (e.g., define ( 'WP_SQLITE_LEGACY_MODE', true );). Would that work for you? cc @wojtekn

[JanJakes]

@sejas Oh, and I just noticed that you're also trying to open a new AST database using the old driver (...translator.php):

[18-Sep-2025 17:46:32 UTC] PHP Fatal error:  Uncaught PDOException: SQLSTATE[HY000]: General error: 11 malformed database schema (_wp_sqlite_mysql_information_schema_schemata) - near "STRICT": syntax error in /srv/htdocs/wp-content/mu-plugins/sqlite-database-integration/wp-includes/sqlite/class-wp-sqlite-translator.php:401

If you use the WP_SQLITE_AST_DRIVER, you'd get an error, such as the following:

The SQLite version 3.27.2 is not supported. Minimum required version is 3.37.0.

[JanJakes]

I drafted a PR in #256.

[sejas]

@JanJakes , thanks for investigating it and sharing more options and context.

I think accessing the STRICT tables trick could work; I'm not sure if there are more unsupported features.

@sejas Alternatively to the warning, I wonder if it would make sense to enable configuring this (e.g., define ( 'WP_SQLITE_LEGACY_MODE', true );). Would that work for you?

I tried defining this constant, but I get the same exact error:

[01-Oct-2025 10:31:24 UTC] PHP Fatal error:  Uncaught PDOException: SQLSTATE[HY000]: General error: 11 malformed database schema (_wp_sqlite_mysql_information_schema_schemata) - near "STRICT": syntax error in /srv/htdocs/wp-content/mu-plugins/sqlite-database-integration/wp-includes/sqlite/class-wp-sqlite-translator.php:401
Stack trace:
#0 /srv/htdocs/wp-content/mu-plugins/sqlite-database-integration/wp-includes/sqlite/class-wp-sqlite-translator.php(401): PDO->query('CREATE TABLE IF...')
#1 /srv/htdocs/wp-content/mu-plugins/sqlite-database-integration/wp-includes/sqlite/class-wp-sqlite-db.php(348): WP_SQLite_Translator->__construct(Object(PDO))
#2 /srv/htdocs/__wp__/wp-includes/class-wpdb.php(773): WP_SQLite_DB->db_connect()
#3 /srv/htdocs/wp-content/mu-plugins/sqlite-database-integration/wp-includes/sqlite/class-wp-sqlite-db.php(55): wpdb->__construct('', Object(SensitiveParameterValue), '151385747', '')
#4 /srv/htdocs/wp-content/mu-plugins/sqlite-database-integration/wp-includes/sqlite/db.php(84): WP_SQLite_DB->__construct('151385747')
#5 /srv/htdocs/wp-content/db.php(37): require_once('/srv/htdocs/wp-...')
#6 /srv/htdocs/__wp__/wp-includes/load.php(708): require_once('/srv/htdocs/wp-...')
#7 /srv/htdocs/__wp__/wp-settings.php(134): require_wp_db()
#8 /srv/htdocs/wp-config.php(88): require_once('/srv/htdocs/__w...')
#9 /srv/htdocs/__wp__/wp-load.php(55): require_once('/srv/htdocs/wp-...')
#10 /srv/htdocs/__wp__/wp-blog-header.php(13): require_once('/srv/htdocs/__w...')
#11 /srv/htdocs/__wp__/index.php(17): require('/srv/htdocs/__w...')
#12 {main}
  thrown in /srv/htdocs/wp-content/mu-plugins/sqlite-database-integration/wp-includes/sqlite/class-wp-sqlite-translator.php on line 401

@sejas Oh, and I just noticed that you're also trying to open a new AST database using the old driver (...translator.php):
[18-Sep-2025 17:46:32 UTC] PHP Fatal error: Uncaught PDOException: SQLSTATE[HY000]: General error: 11 malformed database schema (_wp_sqlite_mysql_information_schema_schemata) - near "STRICT": syntax error in /srv/htdocs/wp-content/mu-plugins/sqlite-database-integration/wp-includes/sqlite/class-wp-sqlite-translator.php:401
If you use the WP_SQLITE_AST_DRIVER, you'd get an error, such as the following:
The SQLite version 3.27.2 is not supported. Minimum required version is 3.37.0.

Defining this constant (define ( 'WP_SQLITE_AST_DRIVER', true );) I get a new error Database directory is not writable: /srv/htdocs/wp-content/database , but the directory remains the same with same permissions and files.

I'm testing on https://antoniosejas-xnufj-studio.wp.build/ and I have SSH access.

[JanJakes]

@sejas

I tried defining this constant, but I get the same exact error

That constant doesn't exist yet, I only meant it as an example of how we could implement it. If you apply the diff from https://github.com/WordPress/sqlite-database-integration/pull/256/files and define WP_SQLITE_UNSAFE_ENABLE_UNSUPPORTED_VERSIONS, would that work? Note that WP_SQLITE_AST_DRIVER need to be defined as well.

I get a new error Database directory is not writable: /srv/htdocs/wp-content/database

Ah, maybe that's what WordPress outputs when we throw the incorrect SQLite version error 🤔 UPDATE: No, it comes from the SQLite plugin. I will take a look and comment in the PR.

[sejas]

Ah!, ok! Gotcha 😅 .

I'm still getting the same weird error about database directory not writable and it doesn't appear any error or output in debug.log. 🤔

[JanJakes]

@sejas That error seems to come from here, and I guess that, indeed, the directory is not writable.

While, technically, you could have write access to the SQLite database but not to its parent directory, I worry that can cause more obscure and unpredictable errors, as SQLite sometimes needs to write temporary files like journal or write-ahead log, and it may fail to do so at some point.

Is there a reason not to have it writable? Normally, wp-content and its subdirectories should be writable for the PHP process.

[sejas]

@JanJakes , do you know why it's a requirement only when AST is activated?

The user that runs PHP is the owner and has read and write permissions for the directory and file.
#252 (comment)

I even set 777 permission for that directory and all the files in it, but is_writable is still returning false. I don't fully understand the reason.

[JanJakes]

@sejas Oh, interesting! Thanks for the investigation. So why does PHP always return false here? 🤔

do you know why it's a requirement only when AST is activated?

It seems to happen rather accidentally — in the old driver, no checks are done when the DB file exists:

sqlite-database-integration/wp-includes/sqlite/class-wp-sqlite-translator.php

Line 357 in 0700853

if ( ! is_file( FQDB ) ) {

But it should be a requirement for the old driver as well (SQLite needs write access to the directory where the DB is stored).

I wonder if we can figure out why it's always false or whether we can use a different check.

For the purposes of this issue, if you remove the is_writable check, does it work for you?

[sejas]

@JanJakes, No, it doesn't work. I also tried commenting the whole $this->ensure_database_directory( FQDB ); check, and I get a 502 Bad Gateway error.

sqlite-database-integration/wp-includes/sqlite/class-wp-sqlite-db.php

Line 332 in 0700853

$this->ensure_database_directory( FQDB );

[sejas]

Regarding the is_writable function, it seems the behavior is related to this plugin. The same check works as expected on the same server when running it in a plain .php file and inside WordPress when this plugin is not loaded.

@JanJakes , Do you want me to open a new issue in this repository?

[JanJakes]

@sejas Strange. I'd like to debug this. Let's connect on Slack.