SqlServer语句收集

来源于：http://www.cnblogs.com/stswordman/archive/2007/03/15/675518.html

SqlServer语句收集

1 临时表

 

--创建临时表 数据库重启后表#a1会消失
create table #a1
(
col1 int,
col2 int
)
select * from #a1

--创建临时表 改表只存在与当前的session

create table ##a2
(
col1 int,
col2 int
)

 

2 从两个表中select

create table ##b1
(
col1 int
)

create table ##b2
(
col2 int
)

insert ##b1 values(1)
insert ##b1 values(2)
insert ##b1 values(3)

insert ##b2 values(2)
insert ##b2 values(1)

select col1,col2 from ##b1,##b2

/*

得到的结果是2*3=6条记录

col1 col2

1      2
2      2
3      2
1     1
2     1
3     1

*/

3  只保留时间的日期部分
select convert(varchar(10), getdate(),120)

   /*

得到如下结果

2007-03-15

*/

 

4  时间的小时,分秒部分归零

declare @date datetime
set @date=getdate()
select DATEADD(day, DATEDIFF(day,0,@date), 0)

 

   /*

 

得到如下结果

2007-03-15 00:00:00.000

*/

5  读取第n条记录以后的记录

declare @n int

set @n=5

select * from 表 where id not in (select top (@n) id from 表)

6 如何得到时间段内的所有日期

给出起始时间和结束时间,然后的到之间的全部日期
例如其时日期为2007-1-1,结束日期为2007-1-5
得到如下结果
2007-1-1
2007-1-2
2007-1-3
2007-1-4
2007-1-5

 

 给出两个方法

1

 

create table #
(
col datetime
)
go
declare @begintime datetime
declare @endtime datetime
declare @day int
set @begintime=cast('2007-1-1' as datetime)
set @endtime =cast('2007-1-5' as datetime)
select @day=DATEDIFF(day, @begintime, @endtime)
while @day>=0
begin
insert into # select dateadd(day,@day,@begintime)
set @day=@day-1
end
select * from #
drop table #

 

2

 

Declare @StartDate DateTime, @EndDate DateTime
Select @StartDate = '2007-1-1' , @EndDate = '2007-1-5'
Select Top 100 Identity(Int, 0, 1) As ID Into #T from Sysobjects A, Sysobjects B
Select
DateAdd(dd, ID, @StartDate) As [Date]
From #T
Where ID <= DateDiff(dd, @StartDate, @EndDate)
Drop table #T

 

 

６Full Join

 

a,b两表数据如下

a:
name chinese
张三 60
李四 70

b:
name english
张三 90
王五 80

希望查询的结果如下:
name chinese english
张三 60 90
李四 70 null
王五 null 90

sql语句如下

Select
IsNull(A.name, B.name) As name,
IsNull(A.chinese, 0) As chinese,
IsNull(B.english, 0) As english
From
A
Full Join
B
On A.name = B.name

 

７　条件语句的放置位置

语句如下:

select a.id,b.id from a

left join b on a.id=b.id and b.date>'2007-1-1'

 

 

select a.id,b.id from a

left join b on a.id=b.id
where b.date>'2007-1-1'

 

两个语句的结果是不一样的,第一个语句是现对b表进行筛选,然后再和a表join

而第二个语句是先join再对整体的join后的结果进行率选,所有可能得到比第一种少的结果集

 

８　对重复记录进行操作

   1 去除重复项

 

select * from table1 where col1 not in
(
select col1 from table1 group by col1 having count(col1)>1
)

   2 只筛选出重复项

 

 

select * from table1 where col1 in
(
select col1 from table1 group by col1 having count(col1)>1
)

 

９　判断是否为数字

ISNUMERIC(expression)

  数字返回1

 非数字返回0

 

10   得到存储过程内容

select text from syscomments where id=object_id('procName')

11  删除所有的存储过程

--使用游标

declare @delProc nvarchar(200)
declare @dll nvarchar(4000)
set @dll=''
set @delProc='drop proc '
declare @procName nvarchar(100)

DECLARE proc_cur CURSOR FOR
SELECT name FROM sysobjects where xtype='p';
OPEN proc_cur;
FETCH NEXT FROM proc_cur
into @procName
WHILE @@FETCH_STATUS = 0
BEGIN
set @dll=@dll+ ' '+ @delProc+@procName

FETCH NEXT FROM proc_cur
into @procname
END;
CLOSE proc_cur;
DEALLOCATE proc_cur;

print @dll

12 事务

BEGIN TRY

     BEGIN TRAN

 

     INSERT INTO table1 (i,col1,col2)

     VALUES (1,'First row','First row');

     INSERT INTO table1 (i,col1,col2)

     VALUES (2,NULL,'Second row');

     INSERT INTO table1 (i,col1,col2)

     VALUES (3,'Third row','Third row');

 

     COMMIT TRAN;

END TRY

BEGIN CATCH

     ROLLBACK TRAN

END CATCH;

 

13 外键约束

create table company
(
id int identity(1,1),
name nvarchar(20) unique
)
create table product
(
id int identity(1,1),
companyid int,
name nvarchar(20) ,
unitprice money,
unique(companyid,name)
)

--添加外键约束

alter table product add constraint fk_company_prodcut
foreign key(companyid)
references company(id) on UPDATE CASCADE ON DELETE CASCADE

 

----删除

alter table product drop constraint  fk_company_prodcut

 

14  触发器

USE tempdb
GO
CREATE TABLE TZ (
Z_id int IDENTITY(1,1)PRIMARY KEY,
Z_name varchar(20) NOT NULL)

CREATE TABLE TY (
Y_id int IDENTITY(100,5)PRIMARY KEY,
Y_name varchar(20) NULL)

/*Create the trigger that inserts a row in table TY
when a row is inserted in table TZ*/
CREATE TRIGGER Ztrigsssss
ON TZ
FOR INSERT,update,delete AS
BEGIN
INSERT TY VALUES ('')
END

15   备份数据库

use master
backup database databaseName to  disk='c:/1.bak'

16字符串拆分
将类似 1,2,3,4,5,6的字符串进行转秩
1
2
3
4
5
6


CREATE   function StrSplit(@str nvarchar(4000),@splitSign nvarchar(10))
returns @table table (itemid int identity(1,1),tempStr nvarchar(3000))
as
   
    begin
        while charindex(@splitSign,@str)>0
            begin
                insert into @table (tempStr)
                select left(@str,charindex(@splitSign,@str)-1)
               
                select @str=stuff(@str,1,charindex(@splitSign,@str)+len(@splitSign)-1,'')

            end   
        insert @table (tempStr) select @str
        return
    end



17  DBCC命令
  DBCC TRACEON(3604)
  DBCC PAGE

  DBCC CheckConstraints(tableName)--检查表中不符合约束的数据

 DBCC ShrinkDatabase

 DBCC ShrinkFile

 

18 Query the DB size

SELECT type_desc ,Sum(Size) FROM sys.database_Files Group by type_desc

 

CREATE TABLE sp_table_pages
(PageFID tinyint,
  PagePID int,
  IAMFID   tinyint,
  IAMPID  int,
  ObjectID  int,
  IndexID  tinyint,
  PartitionNumber tinyint,
  PartitionID bigint,
  iam_chain_type varchar(30),
  PageType  tinyint,
  IndexLevel  tinyint,
  NextPageFID  tinyint,
  NextPagePID  int,
  PrevPageFID  tinyint,
  PrevPagePID int,
  Primary Key (PageFID, PagePID));

TRUNCATE TABLE sp_table_pages;

INSERT INTO sp_table_pages

EXEC ('dbcc ind
 ( AdventureWorks, [Sales.SalesOrderDetail], -1)' );