wp-database

Use when a WordPress plugin needs a custom database table — creating with dbDelta (strict SQL format: two spaces before PRIMARY KEY, no trailing comma), writing versioned upgrade routines with version_compare and register_activation_hook, querying with $wpdb prepared statements (prepare, insert, update, delete, get_row, get_results, get_var), debugging with $wpdb->last_error or SAVEQUERIES, schema migrations between…