SQL2005中T－SQL新增功能

增加了varchar的最大限制本来是8K，现在增加到2GB，定义变量的时候可以使用MAX来设置字段大小。例如varchar（max）；

增加了XML类型

增加了TRY/CATCH功能

Set XACT_ABORT on

BEGIN TRY

……

END TRY

BEGIN CATCH

……

END CATCH

更新功能 WRITE ：替换指定位置的字符串

例如: test.write(“aaaa”,1,1)

快照隔离级别：

ALTER DATABASE AdventureWorks

 SET READ_COMMITTED_SNAPSHOT ON;

示例：

1、create database demo2 —创建数据库

go

use demo2

alter database demo2 set allow_snapshot_isolation on ――设定快照隔离

create table test ――创建表

( tid int not null primary key,

tname varchar(50) not null

)

insert into test values(1,'version1')

insert into test values(2,'version2')

2、 --新建连接

use demo2

begin tran――使用事物，让此更新未处理完成，为了达到锁表的功能

update test set tname='version3' where tid=2

select * from test

3、 --新建连接

use demo2

增加了varchar的最大限制本来是8K，现在增加到2GB，定义变量的时候可以使用MAX来设置字段大小。例如varchar（max）；

增加了XML类型

增加了TRY/CATCH功能

Set XACT_ABORT on

BEGIN TRY

……

END TRY

BEGIN CATCH

……

END CATCH

更新功能 WRITE ：替换指定位置的字符串

例如: test.write(“aaaa”,1,1)

快照隔离级别：

ALTER DATABASE AdventureWorks

 SET READ_COMMITTED_SNAPSHOT ON;

示例：

1、create database demo2 —创建数据库

go

use demo2

alter database demo2 set allow_snapshot_isolation on ――设定快照隔离

create table test ――创建表

( tid int not null primary key,

tname varchar(50) not null

)

insert into test values(1,'version1')

insert into test values(2,'version2')

2、 --新建连接

use demo2

begin tran――使用事物，让此更新未处理完成，为了达到锁表的功能

update test set tname='version3' where tid=2

select * from test

3、 --新建连接

use demo2

set transaction isolation level snapshot

select * from test ――可以查询看看结果。

set transaction isolation level snapshot

select * from test――可以查询看看结果。

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top语句的增强功能

以前的top语句不能放在DML语句中，现在就可以放在DML语句中。

--create a table and insert some data
use demo
go
CREATE TABLE toptest (column1 VARCHAR(150))
go
INSERT INTO toptest VALUES('t1')
INSERT INTO toptest VALUES('t2')
INSERT INTO toptest VALUES('t3')
INSERT INTO toptest VALUES('t4')
INSERT INTO toptest VALUES('t5')
INSERT INTO toptest VALUES('t6')
INSERT INTO toptest VALUES('t7')
INSERT INTO toptest VALUES('t8')
select * from toptest
go

CREATE TABLE toptest2 (column2 VARCHAR(150))
go
INSERT INTO toptest2 VALUES('c1')
INSERT INTO toptest2 VALUES('c2')

--declare 3 variables
DECLARE @a INT
DECLARE @b INT
DECLARE @c INT
--set values
SET @a = 10
SET @b = 5
SELECT @c = @a/@b
--use the calculated expression
SELECT TOP(@c) * FROM toptest
--use a SELECT statement as expression
SELECT TOP(SELECT COUNT(*) FROM toptest2) *
FROM toptest

--DML top
DELETE TOP(2) toptest where column1>'t6'
--this sets 't1' and 't2' to 'hi'
UPDATE TOP(2) toptest SET column1 = 'hi' where column1<='t2'

SELECT * FROM toptest

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新增排序更能

ROW_NUMBER是结果集的顺序, 而不是数据库中纪录存放的原始顺序
RANK()

DENSE_RANK()

use demo
go
create table rankorder
(orderid int,
qty int
)
go
insert rankorder values(30001,10)
insert rankorder values(10001,10)
insert rankorder values(10006,10)
insert rankorder values(40005,10)
insert rankorder values(30003,15)
insert rankorder values(30004,20)
insert rankorder values(20002,20)
insert rankorder values(20001,20)
insert rankorder values(10005,30)
insert rankorder values(30007,30)
insert rankorder values(40001,40)
go
SELECT orderid,qty,
ROW_NUMBER() OVER(ORDER BY qty) AS rownumber,
RANK() OVER(ORDER BY qty) AS rank,
DENSE_RANK() OVER(ORDER BY qty) AS denserank
FROM rankorder
ORDER BY qty

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通用表表达式（CTE）

普通CTE示例：

USE AdventureWorks
GO
WITH SalesCTE(ProductID, SalesOrderID)
AS
(
SELECT ProductID, COUNT(SalesOrderID)
FROM Sales.SalesOrderDetail
GROUP BY ProductID
)
SELECT * FROM SalesCTE

递归CTE示例：

-- Using CTEs Recursively
use demo
go
CREATE TABLE CarParts
(
CarID int NOT NULL,
Part varchar(15),
SubPart varchar(15),
Qty int
)
GO
INSERT CarParts
VALUES (1, 'Body', 'Door', 4)
INSERT CarParts
VALUES (1, 'Body', 'Trunk Lid', 1)
INSERT CarParts
VALUES (1, 'Body', 'Car Hood', 1)
INSERT CarParts
VALUES (1, 'Door', 'Handle', 1)
INSERT CarParts
VALUES (1, 'Door', 'Lock', 1)
INSERT CarParts
VALUES (1, 'Door', 'Window', 1)
INSERT CarParts
VALUES (1, 'Body', 'Rivets', 1000)
INSERT CarParts
VALUES (1, 'Door', 'Rivets', 100)
INSERT CarParts
VALUES (1, 'Door', 'Mirror', 1)
go
select * from CarParts
go

WITH CarPartsCTE(SubPart, Qty)
AS
(
-- Anchor Member (AM):
-- SELECT query that doesn’t refer back to CarPartsCTE
SELECT SubPart, Qty
FROM CarParts
WHERE Part = 'Body'
UNION ALL
-- Recursive Member (RM):
-- SELECT query that refers back to CarPartsCTE
SELECT CarParts.SubPart, CarPartsCTE.Qty * CarParts.Qty
FROM CarPartsCTE
INNER JOIN CarParts ON CarPartsCTE.SubPart = CarParts.Part
WHERE CarParts.CarID = 1
)
--outer query
SELECT SubPart, SUM(Qty) AS TotalNUM
FROM CarPartsCTE
GROUP BY SubPart

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Pivot/UNPivot/Apply

Pivot：行转换成列

UNPivot：列转换成行

Apply：关系运算符允许对表外部的每个行调用指定的表值函数一次。可以在查询的from子句中指定Apply，其方式与使用join关系运算符类似

use demo
go

create table orders
(Customer varchar(10) not null,
product varchar(20) not null,
quantity int not null)
go
insert orders values('Mike', 'Bike',3)
insert orders values('Mike','Chain',2)
insert orders values('Mike','Bike',5)
insert orders values('Lisa','Bike',3)
insert orders values('Lisa','Chain',3)
insert orders values('Lisa','Chain',4)
insert orders values('Lisa','Bike',2)

select * from orders

select * from orders
pivot (sum(quantity) for product in ([Bike],[Chain])) as a
use demo
go
CREATE TABLE SALES1
(
[Year] INT,
Quarter CHAR(2),
Amount FLOAT
)
GO
INSERT INTO SALES1 VALUES (2001, 'Q1', 80)
INSERT INTO SALES1 VALUES (2001, 'Q2', 70)
INSERT INTO SALES1 VALUES (2001, 'Q3', 55)
INSERT INTO SALES1 VALUES (2001, 'Q3', 110)
INSERT INTO SALES1 VALUES (2001, 'Q4', 90)
INSERT INTO SALES1 VALUES (2002, 'Q1', 200)
INSERT INTO SALES1 VALUES (2002, 'Q2', 150)
INSERT INTO SALES1 VALUES (2002, 'Q2', 40)
INSERT INTO SALES1 VALUES (2002, 'Q2', 60)
INSERT INTO SALES1 VALUES (2002, 'Q3', 120)
INSERT INTO SALES1 VALUES (2002, 'Q3', 110)
INSERT INTO SALES1 VALUES (2002, 'Q4', 180)
GO

SELECT * FROM SALES1
PIVOT
(SUM (Amount) --Aggregate the Amount column using SUM
FOR [Quarter] --Pivot the Quarter column into column headings
IN (Q1, Q2, Q3, Q4)) --use these quarters
AS P
GO

select * into temp1 from orders
pivot (sum(quantity) for product in ([Bike],[Chain])) as a

select * from temp1

select customer, product,quantity
froam temp1
unpivot(quantity for product in ([Bike],[Chain])) as a

use demo
go
CREATE TABLE Arrays
(
aid INT NOT NULL IDENTITY PRIMARY KEY,
array VARCHAR(7999) NOT NULL
)
go
INSERT INTO Arrays VALUES('')
INSERT INTO Arrays VALUES('10')
INSERT INTO Arrays VALUES('20,40,30')
INSERT INTO Arrays VALUES('-1,-3,-5')
GO
CREATE FUNCTION function1(@arr AS VARCHAR(7999))
RETURNS @t TABLE(pos INT NOT NULL, value INT NOT NULL)
AS
BEGIN
DECLARE @end AS INT, @start AS INT, @pos AS INT
SELECT @arr = @arr + ',', @pos = 1,
@start = 1, @end = CHARINDEX(',', @arr, @start)
WHILE @end > 1
BEGIN
INSERT INTO @t VALUES(@pos, SUBSTRING(@arr, @start, @end - @start))

SELECT @pos = @pos + 1,
@start = @end + 1, @end = CHARINDEX(',', @arr, @start)
END
RETURN
END
--test
select * from function1('200,400,300')
go

SELECT A.aid, F.*
FROM Arrays AS A
CROSS APPLY function1(array) AS F
go
SELECT A.aid, F.*
FROM Arrays AS A
OUTER APPLY function1(array) AS F
GO

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dll 触发器

use demo
go
CREATE TRIGGER prevent_drop_table ON DATABASE FOR DROP_TABLE
AS
RAISERROR('Not allowed to drop tables.', 10, 1)
PRINT 'DROP TABLE attempt in database ' + DB_NAME() + '.'
PRINT CONVERT (nvarchar (1000),EventData())
ROLLBACK
GO
-- test
CREATE TABLE TestDROP(col1 INT)
go
INSERT INTO TestDROP VALUES(1)

drop talbe testdrop

-- Server
CREATE TRIGGER audit_ddl_logins ON ALL SERVER
FOR CREATE_LOGIN, ALTER_LOGIN, DROP_LOGIN
AS
PRINT 'DDL LOGIN took place.'
PRINT CONVERT (nvarchar (1000),EventData())
GO

-- test
CREATE LOGIN login1 WITH PASSWORD = '123'
ALTER LOGIN login1 WITH PASSWORD = 'xyz'
DROP LOGIN login1