mysql分组查询加条件 mysql分组查询命令

select bt.date, s1t, s1.amt, s2t, s2.amt, s3t, s3.amt, s4t, s4.amt from (select date from base_table group by date) bt left join (select count(status) cnt, sum(amount) .

错误方法:select * from a where age=(select max(age) from a where sex=＂男＂) or age=(select max(age) from a where sex=＂女＂) 解释:先用两个子查询分别把男女.

select max(id),name,max(score) from a group by name

分组查询:SELECT 要显示的列 FROM 表 GROUP BY 要分组的列如:SELECT sname,age,address FROM student GROUP BY address上面就是把地址address列进行分组,显示姓名、年龄还有地址分组查询加条件:SELECT 要显示的列 FROM 表 WHERE 条件 GROUP BY 要分组的列如:SELECT sname,age,address FROM student WHERE age 评论0 0 0

楼主你好,首先你要明白group by 是分组查询的意思 使用group by 关键字时,在select列表中可以指定的项目是有限制的,select语句中仅允许以下几项,1:被分组的列2.

select [userage],tag= case when [userage ] is null then 1 else 0 end from tb order by tag 其实order by 也可以这样用

select distinct class,(select count(a) from tb where flag=1 and tb.class = t.class),(select count(a) from tb where flag=2 and tb.class = t.class),(select count(a) from tb where flag=3 and tb.class = t.class) from tb t group by class,flag嘿嘿,看看结果吧

语句顺序select 选择的列from 表where 查询的2113条件group by 分组属性 having 分组过滤的条件order by 排序属性limit 起始记录5261位置,取记录的条数 其中select 选择.

一使用select子句进行多表查询select 字段名 from 表1,表2 … where 表1.字段 = 表2.字段 and 其它查询条件select a.id,a.name,a.address,a.date,b.math,b.english,b.chinese .

类似于这样select id,data,time,rankfrom(select t.id,t.data,t.time,@rownum:=@rownum+1,if (@id=t.id,@rank:=@rank+1,@rank:=1) as rank,@id:=t.idfrom(select id,data,time from test order by id,time) t,(select @rownum:=9,@id:=null,@rank:=0) a) result;