谈SQL Server 2005中的T-SQL增强(3)

USE demo
GO
CREATE TABLE tt
(
id INT IDENTITY,
c1 VARCHAR(15)
)
GO
INSERT INTO tt VALUES ('r1')
INSERT INTO tt VALUES ('r2')
INSERT INTO tt VALUES ('r5')
INSERT INTO tt VALUES ('r6')
INSERT INTO tt VALUES ('r7')
INSERT INTO tt VALUES ('r8')
INSERT INTO tt VALUES ('r9')
INSERT INTO tt VALUES ('r10')
DECLARE @del AS TABLE (deletedId INT, deletedValue VARCHAR(15))
DELETE tt
OUTPUT DELETED.id, DELETED.c1 INTO @del
WHERE id < 3
SELECT * FROM @del
GO
-----------------------------------------------
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')
--声明3个变量
DECLARE @a INT
DECLARE @b INT
DECLARE @c INT
--赋值
SET @a = 10
SET @b = 5
SELECT @c = @a/@b
--使用计算表达式
SELECT TOP(@c) * FROM toptest
--使用SELECT语句作为条件
SELECT TOP(SELECT COUNT(*) FROM toptest2) *
FROM toptest
--指出top
DELETE TOP(2) toptest where column1>'t6'
--更新top
UPDATE TOP(2) toptest SET column1 = 'hi' where column1<='t2'
SELECT * FROM toptest