MySQL SUM() 带条件的求和方法与多条件的求和方法 | 您所在的位置:网站首页 › i did best in 英语作文 › MySQL SUM() 带条件的求和方法与多条件的求和方法 |
一、单一的求和。 select sum(value) as value from table where user_id = 1 and type = 6 and type_son = 2value 为求和的字段。 as 后面是 sum 求和后给它一个名称。 二、SQL语句中嵌套语句多条件求和。 select (select sum(value) from table where type = 6 and type_son = 1) as xj0, (select sum(value) from table where type = 6 and type_son = 2) as xj1, (select sum(value) from table where type = 3 and type_son = 3) as xj2, (select sum(value) from table where type = 4 and type_son = 3) as xj3 from table where user_id = 1 limit 0,1as 后面是 sum 求和后给它一个名称,这样就不会冲突。 三、与第二个一样,但是不采取语句嵌套的方式求和,而是使用 sum 判断求和。 select sum(IF(type = 6 and type_son = 1,value,NULL)) as xj0, sum(IF(type = 6 and type_son = 2,value,NULL)) as xj1, sum(IF(type = 3 and type_son = 0,value,NULL)) as xj2, sum(IF(type = 4 and type_son = 3,value,NULL)) as xj3 from table where user_id = 1sum(IF('条件判断','求和的字段','NULL不计算')) as '别名' 我觉得第三个的方式比前面两个的方式要好。 YII 2.0 使用 SUM 求和 $v['alls_bonus'] = AccountingLog::find() ->select([" sum( IF(type = 6 and type_son = 1,value,NULL) ) as xj0, sum( IF(type = 6 and type_son = 4,value,NULL) ) as xj1, sum( IF(type = 8 and type_son = 4,value,NULL) ) as xj2, sum( IF(type = 3 and type_son = 1,value,NULL) ) as xj3 "]) ->where(['user_id'=>1]) ->asArray() ->one();注意要在 select 里面加 ["sum........"],否则会报错 |
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