经典SQL语句大全以及50个常用的sql语句 (3)

“where 1=1” 是表示选择全部    “where 1=2”全部不选,
如:
if @strWhere !=\'\' 
begin
set @strSQL = \'select count(*) as Total from [\' + @tblName + \'] where \' + @strWhere 
end
else 
begin
set @strSQL = \'select count(*) as Total from [\' + @tblName + \']\' 
end

我们可以直接写成

错误!未找到目录项。
set @strSQL = \'select count(*) as Total from [\' + @tblName + \'] where 1=1 安定 \'+ @strWhere 2、收缩数据库
--重建索引
DBCC REINDEX
DBCC INDEXDEFRAG
--收缩数据和日志
DBCC SHRINKDB
DBCC SHRINKFILE

3、压缩数据库
dbcc shrinkdatabase(dbname)

4、转移数据库给新用户以已存在用户权限
exec sp_change_users_login \'update_one\',\'newname\',\'oldname\'
go

5、检查备份集
RESTORE VERIFYONLY from disk=\'E:\dvbbs.bak\'

6、修复数据库
ALTER DATABASE [dvbbs] SET SINGLE_USER
GO
DBCC CHECKDB(\'dvbbs\',repair_allow_data_loss) WITH TABLOCK
GO
ALTER DATABASE [dvbbs] SET MULTI_USER
GO

7、日志清除
SET NOCOUNT ON
DECLARE @LogicalFileName sysname,
 @MaxMinutes INT,
 @NewSize INT

USE tablename -- 要操作的数据库名
SELECT  @LogicalFileName = \'tablename_log\', -- 日志文件名
@MaxMinutes = 10, -- Limit on time allowed to wrap log.
 @NewSize = 1  -- 你想设定的日志文件的大小(M)

Setup / initialize
DECLARE @OriginalSize int
SELECT @OriginalSize = size 
 FROM sysfiles
 WHERE name = @LogicalFileName
SELECT \'Original Size of \' + db_name() + \' LOG is \' + 
 CONVERT(VARCHAR(30),@OriginalSize) + \' 8K pages or \' + 
 CONVERT(VARCHAR(30),(@OriginalSize*8/1024)) + \'MB\'
 FROM sysfiles
 WHERE name = @LogicalFileName
CREATE TABLE DummyTrans
 (DummyColumn char (8000) not null)


DECLARE @Counter    INT,
 @StartTime DATETIME,
 @TruncLog   VARCHAR(255)
SELECT @StartTime = GETDATE(),
 @TruncLog = \'BACKUP LOG \' + db_name() + \' WITH TRUNCATE_ONLY\'

DBCC SHRINKFILE (@LogicalFileName, @NewSize)
EXEC (@TruncLog)
-- Wrap the log if necessary.
WHILE @MaxMinutes > DATEDIFF (mi, @StartTime, GETDATE()) -- time has not expired
 AND @OriginalSize = (SELECT size FROM sysfiles WHERE name = @LogicalFileName)  
 AND (@OriginalSize * 8 /1024) > @NewSize  
 BEGIN -- Outer loop.
SELECT @Counter = 0
 WHILE   ((@Counter < @OriginalSize / 16) AND (@Counter < 50000))
 BEGIN -- update
 INSERT DummyTrans VALUES (\'Fill Log\') DELETE DummyTrans
 SELECT @Counter = @Counter + 1
 END
 EXEC (@TruncLog)  
 END
SELECT \'Final Size of \' + db_name() + \' LOG is \' +
 CONVERT(VARCHAR(30),size) + \' 8K pages or \' + 
 CONVERT(VARCHAR(30),(size*8/1024)) + \'MB\'
 FROM sysfiles 
 WHERE name = @LogicalFileName
DROP TABLE DummyTrans
SET NOCOUNT OFF

8、说明:更改某个表
exec sp_changeobjectowner \'tablename\',\'dbo\'

9、存储更改全部表

CREATE PROCEDURE dbo.User_ChangeObjectOwnerBatch
@OldOwner as NVARCHAR(128),
@NewOwner as NVARCHAR(128)
AS

DECLARE @Name    as NVARCHAR(128)
DECLARE @Owner   as NVARCHAR(128)
DECLARE @OwnerName   as NVARCHAR(128)

DECLARE curObject CURSOR FOR 
select \'Name\'    = name,
   \'Owner\'    = user_name(uid)
from sysobjects
where user_name(uid)=@OldOwner
order by name

OPEN   curObject
FETCH NEXT FROM curObject INTO @Name, @Owner
WHILE(@@FETCH_STATUS=0)
BEGIN     
if @Owner=@OldOwner 
begin
   set @OwnerName = @OldOwner + \'.\' + rtrim(@Name)
   exec sp_changeobjectowner @OwnerName, @NewOwner
end
-- select @name,@NewOwner,@OldOwner

FETCH NEXT FROM curObject INTO @Name, @Owner
END

close curObject
deallocate curObject
GO


10、SQL SERVER中直接循环写入数据
declare @i int
set @i=1
while @i<30
begin
    insert into test (userid) values(@i)
    set @i=@i+1
end
案例:
有如下表,要求就裱中所有沒有及格的成績,在每次增長0.1的基礎上,使他們剛好及格:

Name     score

Zhangshan   80

Lishi       59

Wangwu      50

Songquan    69

while((select min(score) from tb_table)<60)

begin

update tb_table set score =score*1.01

where score<60

if  (select min(score) from tb_table)>60

break

else

continue

end

数据开发-经典

1.按姓氏笔画排序:
Select * From TableName Order By CustomerName Collate Chinese_PRC_Stroke_ci_as //从少到多

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