Question

我想过滤一个表，但在表格中有一个user_id列，我想过滤它的真实表格（我的意思是users.username）。

我的代码：

SELECT SQL_CALC_FOUND_ROWS `id`, `user_id`, `payment_type`, 
 `is_paid`, `is_invoiced`, `invoice_number`, `created_at`, `ip`,
 `data`, `coupon_code`, `payment_total`, 
 (select CONCAT(users.name,' ',users.surname) from users where users.id = orders.user_id) as fullname
FROM orders
WHERE (`fullname` LIKE '%M%' OR `payment_type` LIKE '%M%') ORDER BY `is_invoiced` asc

当我执行此操作时，会出现如下错误：Unknown column 'fullname' in 'where clause'。

我该如何解决？

Answer 1

您只能在GROUP BY，ORDER BY或HAVING条款中使用列别名。

来自MySQL文档：

标准SQL不允许您引用WHERE中的列别名条款。强制执行此限制是因为WHERE代码是执行后，列值可能尚未确定

参考：http://dev.mysql.com/doc/refman/5.0/en/problems-with-alias.html

Answer 2

使用HAVING子句。

SELECT SQL_CALC_FOUND_ROWS id, user_id, payment_type, is_paid, 
is_invoiced, invoice_number, created_at, ip, data, coupon_code,
payment_total, (select CONCAT(users.name,' ',users.surname) 
from users where users.id = orders.user_id) as fullname 
FROM orders HAVING (fullname LIKE '%M%' OR payment_type LIKE '%M%') 
ORDER BY is_invoiced asc;

Answer 3

尝试在CONCAT子句中使用WHERE，如：

SELECT SQL_CALC_FOUND_ROWS `id`, `user_id`, `payment_type`, 
`is_paid`, `is_invoiced`, `invoice_number`, `created_at`, `ip`,
`data`, `coupon_code`, `payment_total`, 
(select CONCAT(users.name,' ',users.surname) from users
WHERE CONCAT(users.name,' ',users.surname) LIKE '%M%'
and users.id = orders.user_id) as fullname
FROM orders
WHERE `payment_type` LIKE '%M%' ORDER BY `is_invoiced` asc

concat选择不在where子句中使用（mysql）

3 个答案: