使用语句清除sqlserver数据库日志文件

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