SQL语言

表：user  列：id,name,age,createTime

1、找出表中最小年龄的用户:

　　select min(age) from user ;

     select top 1 age from user order by age;

　　select * from user where age<=all(select age from user);

2、找出名字重复的用户：

　　select * from user where name in (select name from user group by name having(count(name)>1));

3、复制表结构、拷贝表数据，联查：

　　select * into user1 from user where 1=0;

　　select * into user1 from user;

　　select * from user,user1,user2 where 关联条件;

4、SQL Server中创建临时表:

　　create table #temp(字段1 类型，字段2 类型...);临时表在表名前加#

5、最新写入的用户信息:

　　select * from user where createTime = (select max(createTime) from user);

6、取第5行到第7行的用户信息:

　　select * from user order by id limit 4,3;索引从4开始，取三个数据

　　slelect top 3 from user where id not in (select top 4 id from user order by id) order by id ;