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声明变量时必须在变量前加@符号
DECLARE @I INT
变量赋值时变量前必须加set
SET @I = 30
DECLARE @s varchar(10),@a INT
if ..
begin
...
end
else if ..
begin
...
end
else
begin
...
end
Example:
DECLARE @d INT
set @d = 1
IF @d = 1 BEGIN
PRINT ‘正确‘
END
ELSE BEGIN
PRINT ‘错误‘
END
Example:
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
WHILE 条件 BEGIN
执行语句
END
Example:
Java代码 收藏代码
DECLARE @i INT
SET @i = 1
WHILE @i<1000000 BEGIN
set @i=@i+1
END
DECLARE @cur1 CURSOR FOR SELECT .........
OPEN @cur1
FETCH NEXT FROM @cur1 INTO 变量
WHILE(@@FETCH_STATUS=0)
BEGIN
处理.....
FETCH NEXT FROM @cur1 INTO 变量
END
CLOSE @cur1
DEALLOCATE @cur1
AS
declare @CATEGORY_CI_TABLENAME VARCHAR(50) =‘‘
declare @result VARCHAR(2000) = ‘‘
declare @CI_ID DECIMAL = 0
declare @num int = 1
declare @countnum int = 1
BEGIN
select @countnum = count(ATTRIBUTE_CONFIG_ID) from T_ATTRIBUTE_CONFIG where CMDB_UPDATE_FLAG= ‘Y‘ and CATEGORY_CODE =@CATEGORY_CODE
IF (@ATTRIBUTE2=‘A‘)
begin
DECLARE MyCursor CURSOR for select ATTRIBUTE_CONFIG_CODE from T_ATTRIBUTE_CONFIG where CMDB_UPDATE_FLAG= ‘Y‘ and CATEGORY_CODE =@CATEGORY_CODE
OPEN MyCursor FETCH NEXT FROM MyCursor INTO @CONFIG_CODE
set @result = @result+@CONFIG_CODE+‘,‘
WHILE @@FETCH_STATUS = 0
BEGIN
FETCH NEXT FROM MyCursor INTO @CONFIG_CODE
set @num = @num+ 1
if(@num<@countnum)
begin
set @result = @result+@CONFIG_CODE+‘,‘
end
else if(@num=@countnum)
begin
set @result = @result +@CONFIG_CODE
end
END
CLOSE MyCursor
DEALLOCATE MyCursor
set @result = ‘insert into ‘ + @ATTRIBUTE1 + ‘(‘ + @result +‘) select ‘+ @result +‘ from ‘+@CATEGORY_CI_TABLENAME +‘ where CI_ORDER_LINE_ID=‘+@KEY_ID
end
else if((@ATTRIBUTE2=‘U‘))
– Select INTO 从一个查询的计算结果中创建一个新表。 数据并不返回给客户端,这一点和普通的Select 不同。 新表的字段具有和 Select 的输出字段相关联(相同)的名字和数据类型。
select * into NewTable
from Uname
– Insert INTO ABC Select
– 表ABC必须存在
– 把表Uname里面的字段Username复制到表ABC
Insert INTO ABC Select Username FROM Uname
– 创建临时表
Create TABLE #temp(
UID int identity(1, 1) PRIMARY KEY,
UserName varchar(16),
Pwd varchar(50),
Age smallint,
Sex varchar(6)
)
– 打开临时表
Select * from #temp
临时表对执行效率应该影响不大,只要不是太过份,相反可以提高效率特别是连接查询的地方,只要你的数据库临时表空间足够
游标多,会严重执行效率,能免则免!
SQLSERVER 存储过程 语法
===============================================================================
其他:
–有输入参数的存储过程–
create proc GetComment
(@commentid int)
as
select * from Comment where CommentID=@commentid
–有输入与输出参数的存储过程–
create proc GetCommentCount
@newsid int,
@count int output
as
select @count=count(*) from Comment where NewsID=@newsid
–返回单个值的函数–
create function MyFunction
(@newsid int)
returns int
as
begin
declare @count int
select @count=count(*) from Comment where NewsID=@newsid
return @count
end
–调用方法–
declare @count int
exec @count=MyFunction 2
print @count
–返回值为表的函数–
Create function GetFunctionTable
(@newsid int)
returns table
as
return
(select * from Comment where NewsID=@newsid)
–返回值为表的函数的调用–
select * from GetFunctionTable(2)
以前拼接的写法
set @sql=‘ select * from table where 1=1 ‘
if (@addDate is not null)
set @sql = @sql+‘ and addDate = ‘+ @addDate + ‘ ‘
if (@name <>‘‘ and is not null)
set @sql = @sql+ ‘ and name = ‘ + @name + ‘ ‘
exec(@sql)
下面是 不采用拼接SQL字符串实现多条件查询的解决方案
第一种写法是 感觉代码有些冗余
if (@addDate is not null) and (@name <> ‘‘)
select * from table where addDate = @addDate and name = @name
else if (@addDate is not null) and (@name =‘‘)
select * from table where addDate = @addDate
else if(@addDate is null) and (@name <> ‘‘)
select * from table where and name = @name
else if(@addDate is null) and (@name = ‘‘)
select * from table
第二种写法是
select * from table where (addDate = @addDate or @addDate is null) and (name = @name or @name = ‘‘)
第三种写法是
SELECT * FROM table where
addDate = CASE @addDate IS NULL THEN addDate ELSE @addDate END,
name = CASE @name WHEN ‘‘ THEN name ELSE @name END
–简单赋值
declare @a int
set @a=5
print @a
–使用select语句赋值
declare @user1 nvarchar(50)
select @user1= ‘张三‘
print @user1
declare @user2 nvarchar(50)
select @user2 = Name from ST_User where ID=1
print @user2
–使用update语句赋值
declare @user3 nvarchar(50)
update ST_User set @user3 = Name where ID=1
print @user3
–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
–while循环计算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
--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
declare @ID int
declare @Oid int
declare @Login varchar (50)
–定义一个游标
declare user_cur cursor for select ID,Oid,[Login] from ST_User
–打开游标
open user_cur
while @@fetch_status=0
begin
–读取游标
fetch next from user_cur into @ID,@Oid,@Login
print @ID
--print @Login
end
close user_cur
–摧毁游标
deallocate user_cur
触发器中的临时表:
Inserted
存放进行insert和update 操作后的数据
Deleted
存放进行delete 和update操作前的数据
–创建触发器
Create trigger User_OnUpdate
On ST_User
for Update
As
declare @msg nvarchar(50)
--@msg记录修改情况
select @msg = N ‘姓名从“‘ + Deleted. Name + N ‘”修改为“‘ + Inserted. Name + ‘”‘ from Inserted,Deleted
–插入日志表
insert into [LOG](MSG) values (@msg)
–删除触发器
drop trigger User_OnUpdate
–创建带output参数的存储过程
CREATE PROCEDURE PR_Sum
@a int ,
@b int ,
@ sum int output
AS
BEGIN
set @ sum =@a+@b
END
–创建Return返回值存储过程
CREATE PROCEDURE PR_Sum2
@a int ,
@b int
AS
BEGIN
Return @a+@b
END
–执行存储过程获取output型返回值
declare @mysum int
execute PR_Sum 1,2,@mysum output
print @mysum
–执行存储过程获取Return型返回值
declare @mysum2 int
execute @mysum2= PR_Sum2 1,2
print @mysum2
函数的分类:
1)标量值函数
2)表值函数
a:内联表值函数
b:多语句表值函数
3)系统函数
–新建标量值函数
create function FUNC_Sum1
(
@a int ,
@b int
)
returns int
as
begin
return @a+@b
end
–新建内联表值函数
create function FUNC_UserTab_1
(
@myId int
)
returns table
as
return ( select * from ST_User where ID<@myId)
–新建多语句表值函数
create function FUNC_UserTab_2
(
@myId int
)
returns @t table
(
[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
)
as
begin
insert into @t select * from ST_User where ID<@myId
return
end
–调用表值函数
select * from dbo.FUNC_UserTab_1(15)
--调用标量值函数
declare @s int
set @s=dbo.FUNC_Sum1(100,50)
print @s
–删除标量值函数
drop function FUNC_Sum1
谈谈自定义函数与存储过程的区别:
一、自定义函数:
1. 可以返回表变量
2. 限制颇多,包括
不能使用output参数;
不能用临时表;
函数内部的操作不能影响到外部环境;
不能通过select返回结果集;
不能update,delete,数据库表;
3. 必须return 一个标量值或表变量
自定义函数一般用在复用度高,功能简单单一,争对性强的地方。
二、存储过程
1. 不能返回表变量
2. 限制少,可以执行对数据库表的操作,可以返回数据集
3. 可以return一个标量值,也可以省略return
存储过程一般用在实现复杂的功能,数据操纵方面。
SqlServer存储过程–实例
实例1:只返回单一记录集的存储过程。
表银行存款表(bankMoney)的内容如下
Id | userID | Sex | Money |
---|---|---|---|
001 | Zhangsan | 男 | 30 |
002 | Wangwu | 男 | 50 |
003 | Zhangsan | 男 | 40 |
要求1:查询表bankMoney的内容的存储过程
create procedure sp_query_bankMoney
as
select * from bankMoney
go
exec sp_query_bankMoney
注* 在使用过程中只需要把T-Sql中的SQL语句替换为存储过程名,就可以了很方便吧!
实例2(向存储过程中传递参数):
加入一笔记录到表bankMoney,并查询此表中userID= Zhangsan的所有存款的总金额。
Create proc insert_bank @param1 char(10),@param2 varchar(20),@param3 varchar(20),@param4 int,@param5 int output
with encryption ---------加密
as
insert into bankMoney (id,userID,sex,Money)
Values(@param1,@param2,@param3, @param4)
select @param5=sum(Money) from bankMoney where userID=‘Zhangsan‘
go
在SQL Server查询分析器中执行该存储过程的方法是:
declare @total_price int
exec insert_bank ‘004‘,‘Zhangsan‘,‘男‘,100,@total_price output
print ‘总余额为‘+convert(varchar,@total_price)
go
在这里再啰嗦一下存储过程的3种传回值(方便正在看这个例子的朋友不用再去查看语法内容):
传回值的区别:
output和return都可在批次程式中用变量接收,而recordset则传回到执行批次的客户端中。
实例3:使用带有复杂 SELECT 语句的简单过程
下面的存储过程从四个表的联接中返回所有作者(提供了姓名)、出版的书籍以及出版社。该存储过程不使用任何参数。
USE pubs
IF EXISTS (SELECT name FROM sysobjects
WHERE name = ‘au_info_all‘ AND type = ‘P‘)
DROP PROCEDURE au_info_all
GO
CREATE PROCEDURE au_info_all
AS
SELECT au_lname, au_fname, title, pub_name
FROM authors a INNER JOIN titleauthor ta
ON a.au_id = ta.au_id INNER JOIN titles t
ON t.title_id = ta.title_id INNER JOIN publishers p
ON t.pub_id = p.pub_id
GO
au_info_all 存储过程可以通过以下方法执行:
EXECUTE au_info_all
-- Or
EXEC au_info_all
-- 如果该过程是批处理中的第一条语句,则可使用:
au_info_all
实例4:使用带有参数的简单过程
CREATE PROCEDURE au_info
@lastname varchar(40),
@firstname varchar(20)
AS
SELECT au_lname, au_fname, title, pub_name
FROM authors a INNER JOIN titleauthor ta
ON a.au_id = ta.au_id INNER JOIN titles t
ON t.title_id = ta.title_id INNER JOIN publishers p
ON t.pub_id = p.pub_id
WHERE au_fname = @firstname
AND au_lname = @lastname
GO
au_info 存储过程可以通过以下方法执行:
EXECUTE au_info ‘Dull‘, ‘Ann‘
-- Or
EXECUTE au_info @lastname = ‘Dull‘, @firstname = ‘Ann‘
-- Or
EXECUTE au_info @firstname = ‘Ann‘, @lastname = ‘Dull‘
-- Or
EXEC au_info ‘Dull‘, ‘Ann‘
-- Or
EXEC au_info @lastname = ‘Dull‘, @firstname = ‘Ann‘
-- Or
EXEC au_info @firstname = ‘Ann‘, @lastname = ‘Dull‘
-- 如果该过程是批处理中的第一条语句,则可使用:
au_info ‘Dull‘, ‘Ann‘
-- Or
au_info @lastname = ‘Dull‘, @firstname = ‘Ann‘
-- Or
au_info @firstname = ‘Ann‘, @lastname = ‘Dull‘
* 实例5:使用带有通配符参数的简单过程*
CREATE PROCEDURE au_info2
@lastname varchar(30) = ‘D%‘,
@firstname varchar(18) = ‘%‘
AS
SELECT au_lname, au_fname, title, pub_name
FROM authors a INNER JOIN titleauthor ta
ON a.au_id = ta.au_id INNER JOIN titles t
ON t.title_id = ta.title_id INNER JOIN publishers p
ON t.pub_id = p.pub_id
WHERE au_fname LIKE @firstname
AND au_lname LIKE @lastname
GO
au_info2 存储过程可以用多种组合执行。下面只列出了部分组合:
EXECUTE au_info2
-- Or
EXECUTE au_info2 ‘Wh%‘
-- Or
EXECUTE au_info2 @firstname = ‘A%‘
-- Or
EXECUTE au_info2 ‘[CK]ars[OE]n‘
-- Or
EXECUTE au_info2 ‘Hunter‘, ‘Sheryl‘
-- Or
EXECUTE au_info2 ‘H%‘, ‘S%‘
= ‘proc2‘
实例6:if…else
存储过程,其中@case作为执行update的选择依据,用if…else实现执行时根据传入的参数执行不同的修改.
–下面是if……else的存储过程:
if exists (select 1 from sysobjects where name = ‘Student‘ and type =‘u‘ )
drop table Student
go
if exists (select 1 from sysobjects where name = ‘spUpdateStudent‘ and type =‘p‘ )
drop proc spUpdateStudent
go
create table Student
(
fName nvarchar (10),
fAge
smallint ,
fDiqu varchar (50),
fTel int
)
go
insert into Student values (‘X.X.Y‘ , 28, ‘Tesing‘ , 888888)
go
create proc spUpdateStudent
(
@fCase int ,
@fName nvarchar (10),
@fAge smallint ,
@fDiqu varchar (50),
@fTel int
)
as
update Student
set fAge = @fAge, -- 传 1,2,3 都要更新 fAge 不需要用 case
fDiqu = (case when @fCase = 2 or @fCase = 3 then @fDiqu else fDiqu end ),
fTel = (case when @fCase = 3 then @fTel else fTel end )
where fName = @fName
select * from Student
go
-- 只改 Age
exec spUpdateStudent
@fCase = 1,
@fName = N‘X.X.Y‘ ,
@fAge = 80,
@fDiqu = N‘Update‘ ,
@fTel = 1010101
-- 改 Age 和 Diqu
exec spUpdateStudent
@fCase = 2,
@fName = N‘X.X.Y‘ ,
@fAge = 80,
@fDiqu = N‘Update‘ ,
@fTel = 1010101
-- 全改
exec spUpdateStudent
@fCase = 3,
@fName = N‘X.X.Y‘ ,
@fAge = 80,
@fDiqu = N‘Update‘ ,
@fTel = 1010101
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原文地址:http://blog.csdn.net/u011404265/article/details/51800973