Question

public function deleteCustomerFunc($CustID)
{   
    $sql = "DELETE customer, cargo
    FROM customer AS cust, cargo AS car
    WHERE cust.CustID = car.CustID
    AND CustID='$CustID'";

    $result = mysql_query($sql);
    return $result;
}

我有2张桌子：

1）客户-CustID -Primary key 2）货物 - id -primary key，CustID =外键

Answer 1

特定的错误消息会有所帮助。但是，我最初的猜测是你的AND子句不明确 - CustID可以引用cust或car表。虽然在这种情况下哪一个并不重要，但解释器不知道这一点，你需要指定其中一个。

public function deleteCustomerFunc($CustID)
{   
    $sql = "DELETE customer, cargo
    FROM customer AS cust, cargo AS car
    WHERE cust.CustID = car.CustID
    AND cust.CustID='$CustID'";

    $result = mysql_query($sql);
    return $result;
}

Answer 2

首先，DELETE语法不包含字段：

DELETE FROM [tablename] WHERE [condition]

其次，你不能从一个表达式中的两个表中删除，一次只能删除一个。

Answer 3

也许您应该考虑将其设置为级联删除。然后当您从第一个表中删除时，它将通过外键自动从第二个表中删除。

How do I use on delete cascade in mysql?

删除2表的查询无效

3 个答案: