Add WP_SQLITE_DB_NAME constant to take precedence over DB_NAME

[sejas]

• Related to Upgrade SQLite database integration plugin to fix preview sites Automattic/studio#1839

Because filters actually don’t work in db.php, I suggest removing the wp_sqlite_default_db_name filter and introducing a new constant WP_SQLITE_DB_NAME to take precedence over DB_NAME.

• Break your database connection:
  • Edit your wp-config.php
  • Copy the value of your DB_NAME
  • Change it to any value to break your database connection
  • Access the homepage of your site and observe the error: Error establishing a database connection
• Fix your database connection using the new constant:
  • Edit your wp-config.php
  • Add the new constant WP_SQLITE_DB_NAME with the value you copied before. Example define( 'WP_SQLITE_DB_NAME', 'database_name_here' );
  • Access your site and observe it loads correctly

Credit to @wojtekn for the code. I just removed the filter as it seemed misleading.

[sejas]

@JanJakes , what do you think about using this constant to override the DB_NAME?

[sejas]

I added the prefix WP_SQLITE_ to be consistent with other constants required by this plugin, such as WP_SQLITE_AST_DRIVER.

[sejas]

• This PR might not be necessary anymore if we make the plugin more flexible in: Inject database name in queries dynamically #262

[epeicher]

Thanks @sejas for improving this! I’ve tested it, and can confirm that after breaking the connection, applying these changes, and adding the new constant, the site works again.

This LGTM, so I’m accepting the PR, but leaving it to you or someone from the team to decide whether to merge it.

Database name incorrect	Adding the constant	Refreshing the site