Use $wpdb->query()
instead of dbDelta()
function my_plugin_remove_database() {
global $wpdb;
$table_name = $wpdb->prefix . "my_plugin_table";
$sql = "DROP TABLE IF EXISTS $table_name;";
$wpdb->query($sql);
delete_option("my_plugin_db_version");
}
register_deactivation_hook( __FILE__, 'my_plugin_remove_database' );
dbDelta()
does not supported DROP TABLE query.