The code is exactly the same, but an error is reported. What does this error mean?

Question

下面是报错的内容

Fatal error: Uncaught PDOException: SQLSTATE[42S22]: Column not found: 1054 Unknown column 'class_id' in 'where clause' in D:\PHP\xiaopi\phpstudy_pro\WWW\lyj.com\index.php:58 Stack trace: #0 D:\PHP\xiaopi\phpstudy_pro\WWW\lyj.com\index.php(58): PDOStatement->execute() #1 {main} thrown in D:\PHP\xiaopi\phpstudy_pro\WWW\lyj.com\index.php on line 58

Answer 1

Translate, there is something wrong with class_id