cem ekkazan's questions

我有两张这样的桌子；

发票

id | total_amount | currency | discount

付款

id | invoice | amount

正如您所猜测的，付款表保存对特定发票的付款记录。

我需要查询以获取已部分支付的发票；

SELECT
    invoices.*,
    SUM(payments.amount) as paid
FROM
    invoices
LEFT JOIN
    payments ON payments.invoice = invoices.id
GROUP BY
    invoices.id

我能够通过此查询获得付款金额，但我也需要做类似的事情

WHERE paid < total_amount AND paid > 0

但这表示“未知列在‘where 子句’中‘付费’”。我怎样才能得到这份工作？