MySQL alter table查詢的正確語法是什么？

Question

當我嘗試運行以下mysqli調用時

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

返回錯誤

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

單引號（ ' ）表示字符串文字。 對象名稱（例如列）不是字符串-突出號將引起引號：

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

Answer 2

嘗試更改“標記”以這樣標記 ：

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

Answer 3

只需刪除'標記附近的引號

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