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sql 嵌套sElECt语句

在一个SELECT 语句的WHERE 子句或HAVING 子句中嵌套另一个SELECT 语句的查询称为嵌套查询,又称子查询。子查询是SQL 语句的扩展,例如下: select * from table1 where xh in (select xh from table2)

--方法一select top 10 from (select * from sysobjects) as a where 1=1-- 方法二with ts as (select * from sysobjects)select top 10 * from ts where 1=1

1,简单子查询; select name,age from person where age > ( select age from person where name = '孙权' ) 2,in嵌套查询; select name from person where countryid in ( select countryid from country where countryname = '魏国' ) 3,s...

select a,b,c from tableD where a=(select a from tableD)

可以。 SQL嵌套SELECT语句是很常见的SQL语句,下面就为您详细介绍SQL嵌套SELECT语句的语法,并附相关示例,供您参考学习之用。 嵌套SELECT语句也叫子查询,一个SELECT 语句的查询结果能够作为另一个语句的输入值。子查询不但能够出现在Where子句...

在VALUES子句中不能有子查询,这样就可以了: insert into VoteRecord(IP,TopicNum) select '" + ip + "',ID from Topic where [Content]='" + topic + "' 实际生成的语句应该这样: insert into VoteRecord(IP,TopicNum) select '192.168.1.1',...

可以的,而且使用频率还比较高。 例:字段:性别 以1和2,分别代表男和女 xb 1 2 1 那么检索的时候可以写: select case when xb = '1' then‘男’when '2' then '女' else '' end

select a.* from tb_content as a inner join tb_friends as b on b.attractior=a.author where b.fans='小兔' order by a.id desc sql改成这样试试。

你的sql写错了,注意你的 and 后面不是一个“判断”,没有 =,也没有in相关的。 根据你的意识,我推断应该这样写 SELECT * FROM ecm_goods a WHERE a.goods_id in ( select b.goods_id from ecm_category_goods b where b.cate_id=1338 )

SELECT EmployeeID,Name,Address, case when DepartmentID ='1' then '财务部' when DepartmentID ='2' then '人力资源部' when DepartmentID = '3' then '经理办公室' when DepartmentID ='4' then '研发部' when DepartmentID = '5' then '市...

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