如何编辑此mySQL查询以不选择2列中具有相同值的行？

Question

运行以下查询我收到以下消息

无效使用group by

SELECT COUNT( id ) AS pages,
       hash, MIN( DATE( TIMESTAMP ) ) AS FirstVisit, 
       MAX( DATE( TIMESTAMP ) ) AS LastVisit
       FROM behaviour
       WHERE MIN( DATE( TIMESTAMP ) ) != MAX( DATE( TIMESTAMP ) )
       GROUP BY hash

如何编辑此查询以便不显示FirstVisit等于LastVisit的行？

Answer 1

聚合函数can't be used in where clause, but can be used in have`中使用。

尝试这个：

SELECT
     COUNT( id ) AS pages,
     hash,
     MIN( DATE( TIMESTAMP ) ) AS FirstVisit,
     MAX( DATE( TIMESTAMP ) ) AS LastVisit
FROM behaviour 
GROUP BY hash
HAVING MIN( DATE( TIMESTAMP ) ) != MAX( DATE( TIMESTAMP ) )