mysql - 在 mysql WHERE 子句中使用 GROUP_CONCAT 和 FIND_IN_SET

Question

我有这个查询，想使用学生电子邮件从表中获取约会数据，但出现此错误 Unknown column 'stu' in 'where clause'

select a.*, GROUP_CONCAT(e.value) as stu FROM wp_ea_appointments a join
wp_ea_fields e on a.id = e.app_id WHERE a.date > DATE('2019-02-14') AND
FIND_IN_SET('jan@gmail.com' , stu ) GROUP BY a.id

Answer 1

FIND_IN_SET条件应该包含在HAVING语句中，而不是WHERE语句中，因为你想在分组后过滤数据

SELECT a.*, 
    GROUP_CONCAT(e.value) as stu 
FROM wp_ea_appointments a 
JOIN wp_ea_fields e ON a.id = e.app_id 
WHERE a.date > DATE('2019-02-14')
GROUP BY a.id
HAVING FIND_IN_SET('jan@gmail.com', stu)