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sql语句 带条件统计不重复的个数 orAClE

可以使用数据库 distinct 去出重复数据及count()统计行数的函数来实现改功能 select name,count(distinct pid) as num from emp where youxi='优秀' group by name

典型的case when 语句块可以解决.先映射表的视图,添加条件过滤 例如性别为M的和为F的分别计数name,可以写成: select b1.sex, count(b1.name) from ((select bh.*, (case when sex= 'M' then 1 else 0 end) as qty /*此处可写多个when*/ from u...

友善的提醒两点,如有帮助还望采纳,谢谢! 第一、你这个语句本身写的有点麻烦,简化如下 SELECT [Store_Abbreviation] ,[Goodname], [Goodmodel] ,SUM(Order_Quantity) AS Order_Quantity, [Workid]from [fangtaidata].[dbo].[SalesStatistics]...

实际上题目考察的就是分组求和。可以通过sum进行求和,count进行数值计算,通过group by进行分组。 sql:select username ,count(accountNo) as count,sum(amount) as amount from tablename group by username; 以上就可以求出username下,acco...

可以通过district来取出字段,之后通过count计算总数量。 sql:select count(district id) from tablename; 如果id字段没有空值的话,可以通过count统计字段的总数量(字段内容可能重复)。 sql:select count(id) from tablename;

select a.* from table a,table bwhere a.id = b.id and a.no b.noand a.id in (select a.id from table a,table c where a.id=c.id group by a.id having count(*)>2) 你这三个表是同一个表不? 还是你为了简单都写成table了? 还有等于2条的怎...

通过where .....and (or)...语句进行多条件查询即可。 sql:select * from tablename t where t.id =1 and t.name ='zhangsan'. 解释:and的意思是 “并且”,两个条件同时满足的话才会输出。上面的sql意思就是:从tablename表中查询出id是1并且...

select sum(case when con1||con2='11' then count else 0 end) 三星笔记本, sum(case when con1||con2='12' then count else 0 end) 三星台式机, sum(case when con1||con2='22' then count else 0 end) 苹果笔记本, sum(case when con1||con2=...

SELECT COUNT ( DISTINCT b ) FROM table1 要这样的结果么?

select * from (select 姓名,身份证,家庭住址,银行帐号,备注,row_number() over (partition by 姓名,身份证 order by numrow desc) ssfrom (select 姓名,身份证,家庭住址,银行帐号,备注,row_number() over (partition by 姓名,身份证 order by ...

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