mysql group_concat()函数 长度限制修改办法

group_concat函数的功能是将某一字段的值按指定的字符进行累加，系统默认的分隔符是逗号

注意：group_concat 函数有长度限制，默认长度是1024，可以使用以下两个方法解决：

转自： https://www.pianshen.com/article/73801583369/

换其他数据库一个 sum() over (partition by ... )就解决了..

mysql比较麻烦, 可以试下

select a.Daytime,sum(new_Role)

from (select distinct DATE_FORMAT(createtime,'%Y-%m-%d') as Daytime)

from `actors` WHERE ( (`createtime` >= '2019-02-01 00:00:00') AND (`createtime` <= '2019-02-11 24:00:00') )

) a

left join (select * from `actors`

WHERE ( (`createtime` >= '2019-02-01 00:00:00') AND (`createtime` <= '2019-02-11 24:00:00') )

)b

on a.Daytime>=b.createtime

group by a.Daytime

order by 1

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