项目中遇到的mysql group by having

1、group 不要 组内，组外排序；

组内排序（若order by it.addtime ASC 写入groupby 后，不创建临时表，那么是分组之后的排序）：

组内排序（http://blog.csdn.net/shellching/article/details/8292338）：

SELECT
*
FROM
(
SELECT
it.money,
it.user_id
FROM
table1 it
LEFT JOIN table2 p ON p.iuser_uid = it.user_id
LEFT JOIN table3 act ON act.activities_code = p.plat
WHERE
(act.pid = 14)
AND (
(it.addtime >= 1467734400)
AND (it.addtime < 1467993600)
)
AND (
(it.money >= 0)
AND (it.money <= 10000000000)
)
ORDER BY
it.addtime ASC
) AS i
GROUP BY
i.user_id;

组外排序：

SELECT
it.money,
it.user_id
FROM
table1 it
LEFT JOIN table2 p ON p.iuser_uid = it.user_id
LEFT JOIN table3 act ON act.activities_code = p.plat
WHERE
(act.pid = 14)
AND (
(it.addtime >= 1467734400)
AND (it.addtime < 1467993600)
)
AND (
(it.money >= 0)
AND (it.money <= 10000000000)
)
GROUP BY
it.user_id
ORDER BY
it.addtime ASC

2、having分组

错误的写法举例（mysql error: Invalid use of group function）：

SELECT
sum(it.money) as sum_money,
it.user_id
FROM
table1 it
LEFT JOIN table2 p ON p.iuser_uid = it.user_id
LEFT JOIN table3 act ON act.activities_code = p.plat
WHERE
(act.pid = 14)
AND (
(it.addtime >= 1467734400)
AND (it.addtime < 1467993600)
)
AND (
(sum(it.money) >= 0)
AND (sum(it.money) <= 10000000000)
)
GROUP BY
it.user_id
;

对于上语句，应采用having来进行记录刷选（参考：http://www.jb51.net/article/32562.htm）：

SELECT
sum(it.money) as sum_money,
it.user_id
FROM
table1 it
LEFT JOIN table2 p ON p.iuser_uid = it.user_id
LEFT JOIN table3 act ON act.activities_code = p.plat
WHERE
(act.pid = 14)
AND (
(it.addtime >= 1467734400)
AND (it.addtime < 1467993600)
)
GROUP BY
it.user_id
HAVING
(sum(it.money) >= 0)
AND (sum(it.money) <= 10000000000)
;