1、官方文档:
count:COUNT(
expr
) [over_clause
]
https://dev.mysql.com/doc/refman/8.0/en/group-by-functions.html#function_count
1.1 实例:
select update_time,sid,group_concat(if(age > ‘1‘, tid, NULL)),count(DISTINCT if(age =1,tid,null)) as current_t
from tb_s_members group by update_time,sid order by update_time desc
2、group_concat 官方文档:
GROUP_CONCAT([DISTINCT] expr [,expr ...]
[ORDER BY {unsigned_integer | col_name | expr}
[ASC | DESC] [,col_name ...]]
[SEPARATOR str_val])
https://dev.mysql.com/doc/refman/8.0/en/group-by-functions.html#function_group-concat
原文地址:https://www.cnblogs.com/cbugs/p/9340751.html
时间: 2024-11-05 19:11:42