带有count的mysql查询会出错

Question

以下mysql查询...

SELECT a.*, b.*,
       ( 
            SELECT COUNT( * ) 
            FROM lp_units c 
            WHERE c.property_id = a.property_id 
        ) AS unitcount
FROM lp_property a,
     lp_property_confidential b
WHERE a.property_id = b.property_id
AND c.unitcount<= a.no_of_units
AND a.account_id = '1'

返回错误...

Unknown column 'c.unitcount' in 'where clause'

我认为我的查询是可以理解的。解决它运行....

提前致谢...

Answer 1

请勿使用c.unitcount。只需unitcount。 unitcount不是c的列，而是子查询生成的临时表。

但是，无论如何，这个查询可能最好写成一个连接。

尝试此查询

SELECT
  a.*,
  b.*,
  COUNT(c.property_id) as unitcount
  FROM lp_property a
  JOIN lp_property_confidential b ON a.property_id = b.property_id
  JOIN lp_units c ON c.property_id = a.property_id
  WHERE
  a.account_id = '1'
  GROUP BY a.property_id
  HAVING unitcount <= a.no_of_units