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原创 sum(case when status=1 then 1 else 0 end)

以下有两张表,需要合并按投资额度倒序排序SELECT time 时间, sum(case when score= "90" then 1 else 0 end) as 胜,sum(case when result = "负" then 1 else 0 end) as 负 from Student GROUP BY time;简要说明:when score= “90” : 为判断条件,then 1 selse 0 end: 当以上判断条件成立,则为1; 而该语句是在sum中的,具有累加效果,