Mysql——case函数
select 时间,SUM(case when win='胜' then 1 else 0 end) 胜,SUM(case when win='负' then 1 else 0 end) 负from tbgroup by 时间
case相当于if.....else 条件语句
select 时间,SUM(case when win='胜' then 1 else 0 end) 胜,SUM(case when win='负' then 1 else 0 end) 负from tbgroup by 时间
case相当于if.....else 条件语句