SqlServer表、临时表、表变量和常用逻辑处理操作
---------------表、临时表、表变量-----------------
--创建临时表1
create table #DU_User1
(
[ID] [ int ] NOT NULL ,
[Oid] [ int ] NOT NULL ,
[Login] [nvarchar](50) NOT NULL ,
[Rtx] [nvarchar](4) NOT NULL ,
[ Name ] [nvarchar](5) NOT NULL ,
[ Password ] [nvarchar]( max ) NULL ,
[State] [nvarchar](8) NOT NULL
);
--向临时表1插入一条记录
insert into #DU_User1 (ID,Oid,[Login],Rtx, Name ,[ Password ],State) values (100,2, 'LS' , '0000' , '临时' , '321' , '特殊' );
--从ST_User查询数据，填充至新生成的临时表
select * into #DU_User2 from ST_User where ID<8
--查询并联合两临时表
select * from #DU_User2 where ID<3 union select * from #DU_User1
--删除两临时表
drop table #DU_User1
drop table #DU_User2
--创建临时表
CREATE TABLE #t
(
[ID] [ int ] NOT NULL ,
[Oid] [ int ] NOT NULL ,
[Login] [nvarchar](50) NOT NULL ,
[Rtx] [nvarchar](4) NOT NULL ,
[ Name ] [nvarchar](5) NOT NULL ,
[ Password ] [nvarchar]( max ) NULL ,
[State] [nvarchar](8) NOT NULL ,
)
--将查询结果集（多条数据）插入临时表
insert into #t select * from ST_User
--不能这样插入
--select * into #t from dbo.ST_User
--添加一列，为int型自增长子段
alter table #t add [myid] int NOT NULL IDENTITY(1,1)
--添加一列，默认填充全球唯一标识
alter table #t add [myid1] uniqueidentifier NOT NULL default (newid())
select * from #t
drop table #t
--给查询结果集增加自增长列
--无主键时：
select IDENTITY( int ,1,1) as ID, Name ,[Login],[ Password ] into #t from ST_User
select * from #t
--有主键时：
select ( select SUM (1) from ST_User where ID<= a.ID) as myID,* from ST_User a order by myID
--定义表变量
declare @t table
(
id int not null ,
msg nvarchar(50) null
)
insert into @t values (1, '1' )
insert into @t values (2, '2' )
select * from @t
----------逻辑处理操作-----------
---while：while计算1到100的和
declare @a int
declare @ sum int
set @a=1
set @ sum =0
while @a<=100
begin
set @ sum +=@a
set @a+=1
end
print @ sum
--条件语句-----
--if,else条件分支
if(1+1=2)
begin
print '对'
end
else
begin
print '错'
end
--when then条件分支
declare @today int
declare @week nvarchar(3)
set @today=3
set @week= case
when @today=1 then '星期一'
when @today=2 then '星期二'
when @today=3 then '星期三'
when @today=4 then '星期四'
when @today=5 then '星期五'
when @today=6 then '星期六'
when @today=7 then '星期日'
else '值错误'
end
print @week
