我可以在 mysql select 语句中使用 Php 函数吗？

Question

我正在尝试使用 getCity() 函数获取 cit 名称，但不幸的是它对我不起作用。 请帮忙。

$sql =("
    SELECT
        distinct orders.id as 'Order Id',
        users.email,
        orders.price as 'Amount', 
        orders.at as 'Date and Time',
        '".getCity($id)."' as 'CITY'
    FROM users, orders, order_history, users_address
    WHERE
        users.id = order_history.uid
        AND orders.id = order_history.oid 
        AND orders.real = 1 AND orders.price > 1
        AND orders.payment_status = 1 AND orders.status = 1
    ORDER BY orders.id;
");

Answer 1

您只能使用此函数的结果：

$result = getCity($id);

$sql =("
    SELECT
        distinct orders.id as 'Order Id', 
        users.email, orders.price as 'Amount', 
        orders.at as 'Date and Time',
        '$result' as 'CITY'
    FROM users, orders, order_history, users_address
    WHERE users.id = order_history.uid
        AND orders.id= order_history.oid 
        AND orders.real = 1 AND orders.price > 1
        AND orders.payment_status = 1 AND orders.status = 1
    order by orders.id;
");

在这种情况下， $result只能是字符串。 始终相同的字符串 - 对于您可以从 DB 获取的每一行。

如果$result将是列的名称，则应在查询中不带' 。