当表/存储过程/视图/触发器存在时，将其删除。。。
IF OBJECT_ID(N\'表名/存储过程名/视图/触发器名\',N\'U/P/V/TR\') IS NOT NULL
DROP TABLE/PROCEDURE/VIEW/TRIGGER 表名/存储过程名/视图/触发器名
IF EXISTS(SELECT * FROM SYSOBJECTS WHERE NAME = \'表名/存储过程名/视图/触发器名\' AND TYPE = \'U/P/V/TR\')
DROP TABLE/PROCEDURE/VIEW/TRIGGER 表名/存储过程名/视图/触发器名
select * into 目的库.dbo.表名 from 表名
select * into 目的库.dbo.表名 from 表名 where 1=1 复制表结构与内容
select * into 目的库.dbo.表名 from 表名 where 1=0 只复制表结构
@@IDENTITY --返回最后插入的标识值。
说明：两张关联表，删除主表中已经在副表中没有的信息
delete from table1 where not exists ( select * from table2 where table1.field1=table2.field1 )
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表结构如下
id name age
1 zhangsan 100
2 lisi 200
3 wangwu 100
4 zhaoliou 500
5 qianqi 500
6 werwer 245
7 jopio 786
要求:
1.写一个 sql语句,目的是获得相同age的人的name
select a.[name],a.[age] from [table] a inner join
(
select age from [table]
group by age
having(count(age)>1)
) b
on a.[age] = b.[age]
select [name],[age] from [table]
where [age] in
(
select age from [table] group by [age] having(count([age]) > 1)
)
2.将name中含有\'i\'的字符替换成\'*\'
select replace(name,\'i\',\'*\') from [table]