エラー

以下のエラーがありました。

●ＳＱＬ文エラー1(select * from user_db001 where id=;)Content-type: text/html SQL実行に失敗しました。理由: 1064You have an error in your SQL syntax; check the manual that corresponds to your MariaDB server version for the right syntax to use near '' at line 1
STATUS:You have an error in your SQL syntax; check the manual that corresponds to your MariaDB server version for the right syntax to use near '' at line 1