php - MySQL alter table 查询的正确语法是什么？

Question

当我尝试运行以下 mysqli 调用时

$strSQL3=mysqli_query($connection," alter table mark_list add column 'mark' int(2) " ) or die(mysqli_error($connection));

返回错误

You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near `mark int(2)` at line 1

Answer 1

单引号 (') 表示字符串文字。对象名称(例如列)不是字符串 - 只是去掉了引号:

$strSQL3 = mysqli_query($connection ,"alter table mark_list add column mark int(2)" ) or die(mysqli_error($connection));