create/drop/alter/use/execute
create table [tb_UserInfo]
(
[UserID] [uniqueidentifier] NOT NULL DEFAULT (newid()) PRIMARY KEY,
[UserName] [nvarchar](50) NOT NULL,
[PassWord] [nvarchar](50) NOT NULL,
)
create table [tb_Message]
(
[MessageID] [uniqueidentifier] NOT NULL DEFAULT (newid()) PRIMARY KEY,
[UserID] [uniqueidentifier] NOT NULL,
[MessageBody] [nvarchar](max) NOT NULL,
[PostTime] [datetime] NOT NULL,
)
--单表操作
truncate table [tb_UserInfo] --Clear
insert into [tb_UserInfo] ([UserName], [PassWord]) values ('a','a')
insert into [tb_UserInfo] ([UserName], [PassWord]) values ('b','b')
insert into [tb_UserInfo] ([UserName], [PassWord]) values ('c','c')
alter table [tb_UserInfo] add Column_test int --drop column
alter table [tb_UserInfo] drop column Column_test
select * from [tb_UserInfo] where [UserName] not in ('a','b') --between and/like%/<>/用()组成复杂条件
select count(distinct [UserName]) from [tb_UserInfo]
select [UserName] from [tb_UserInfo] group by [UserName] having [UserName] <> 'a' --有group by就不能有where，而用having作为限制
--多表联查
(select [UserID] from [tb_UserInfo]) union all (select [UserID] from [tb_Message]) --讲2个语句的结果合并（只union会消除重复）/except/intersect取交集
select * from [tb_UserInfo], [tb_Message] where [tb_UserInfo].[UserID] <> [tb_Message].[UserID] --等值联合和不等值联合
select * from [tb_UserInfo] inner join [tb_Message] on [tb_UserInfo].[UserID] = [tb_Message].[UserID] --内部联合和外部联合/left、right以相应的为主，另一边没有则null
--
begin transaction trans_name
update [tb_UserInfo] set [UserName] = 'd', [PassWord] = 'd' where [UserName] = 'b'
delete from [tb_UserInfo] where [UserName] = 'c'
commit --能执行的都执行/rollback全能执行才执行
Create Trigger [tri_name]
On [tb_UserInfo]
for Update, insert, delete
As
if Update([UserName])
begin
select [UserName] + ',' + [UserName] from [tb_UserInfo]
end
select * from sysobjects where xtype='TR' --查看触发器
alter table [tb_UserInfo] enable trigger [tri_name] -- disable
create view [view_UserInfo] as select * from [tb_UserInfo] --视图仅用于简化复杂查询可增删改但限制很多
create unique clustered index [index_UserInfo] on [tb_UserInfo]([UserName], [PassWord]) -- unique = distinct/clustered群集
create table #temp (a int) --放在tempdb中/与session类似所以并发操作安全/##全局临时表,用于不同session共享
--游标和简单编程
declare cursor_name scroll cursor for select [UserID] from [tb_UserInfo] for update
open cursor_name
declare @a [nvarchar](50)
fetch cursor_name into @a
while(@@fetch_status = 0)
begin
print @a
fetch cursor_name into @a
end
close cursor_name
deallocate cursor_name
--scroll/insensitive 否则只读向前/在临时表中创建不影响原有数据
--for read only/update
create procedure [dbo].[sp_test]
(
@UserName [nvarchar](50),
@PassWord [nvarchar](50) output
)
as
select @PassWord = [PassWord] from [tb_UserInfo] where [UserName] = @UserName
execute sp_test 'd','f'
drop procedure sp_test
注：本文引用自http://www.cnblogs.com/hbreset/archive/2008/09/11/1289351.html