在上一篇文章中介绍了如何删除数据库日志文件，但是想想还是不是不方便需要手工操作，于是想结合作业实现自动清理日志文件，在清理日志文件时我加上了条件，当磁盘控空间不足多少M才会清理，下面介绍如何实现该功能。没有阅读上一篇文章的，可以通过传送门阅读(删除数据库日志文件的方法)！

阅读目录

• SQL查询磁盘空间大小
• 存储过程添加作业
• 示例下载

exec master..xp_fixeddrives

GOIF EXISTS(SELECT 1 FROM sysobjects WHERE id=OBJECT_ID(‘usp_p_CreateJob‘))BEGIN    DROP PROC dbo.usp_p_CreateJobENDGOCREATE PROCEDURE dbo.usp_p_CreateJob(    @jobname varchar(100),             @sql VARCHAR(MAX),                          @freqtype varchar(6)=‘day‘,         @fsinterval int=1,                    @time int=235959,                         @description VARCHAR(1000)=‘‘           )AS/*功能：创建SQL作业参数：    @jobname:作业名称    @sql:要执行的命令    @freqtype:时间周期,month 月,week 周,day 日    @fsinterval:相对于每日的重复次数    @time:开始执行时间,对于重复执行的作业,将从0点到23:59分    @description:作业的描述*/ BEGIN    DECLARE @dbname AS VARCHAR(500)    SET @dbname=DB_NAME()            BEGIN TRANSACTION    DECLARE @ReturnCode INT    SELECT @ReturnCode = 0        --添加类别    IF NOT EXISTS (SELECT name FROM msdb.dbo.syscategories WHERE name=‘添加作业‘ AND category_class=1)    BEGIN        EXEC @ReturnCode = msdb.dbo.sp_add_category @class=N‘JOB‘, @type=N‘LOCAL‘, @name=N‘添加作业‘        IF (@@ERROR <> 0 OR @ReturnCode <> 0) GOTO QuitWithRollback    END        --删除作业      DECLARE @JobID BINARY(16)       DECLARE @ErrMsg NVARCHAR(500)          SELECT  @JobID = job_id  FROM msdb.dbo.sysjobs WHERE name = @JobName      IF ( @JobID IS NOT NULL )      BEGIN         -- 检查此作业是否为多重服务器作业        IF ( EXISTS ( SELECT * FROM msdb.dbo.sysjobservers WHERE ( job_id = @JobID ) AND ( server_id <> 0 ) ) )        BEGIN          --多重服务器作业不操作          SET @ErrMsg = ‘无法导入作业"‘ + @JobName + ‘"，因为已经有相同名称的多重服务器作业。‘          RAISERROR (@ErrMsg, 16, 1)           GOTO QuitWithRollback        END        ELSE         BEGIN          -- 删除［本地］作业           EXECUTE msdb.dbo.sp_delete_job @job_name = @JobName          SELECT @JobID = NULL         END       END      SET @JobID = NULL        EXEC @ReturnCode =  msdb.dbo.sp_add_job @job_name=@jobname,             @enabled=1,             @notify_level_eventlog=2,             @notify_level_email=0,             @notify_level_netsend=0,             @notify_level_page=0,             @delete_level=0,             @description=@description,             @category_name=N‘添加作业‘,             @owner_login_name=N‘sa‘, @job_id = @jobId OUTPUT    IF (@@ERROR <> 0 OR @ReturnCode <> 0) GOTO QuitWithRollback    /****** Object:  Step [数据同步]    Script Date: 01/25/2014 23:00:36 ******/    EXEC @ReturnCode = msdb.dbo.sp_add_jobstep @job_id=@jobId, @step_name=@jobname,             @step_id=1,             @cmdexec_success_code=0,             @on_success_action=1,             @on_success_step_id=0,             @on_fail_action=2,             @on_fail_step_id=0,             @retry_attempts=5,             @retry_interval=5,             @os_run_priority=0, @subsystem=N‘TSQL‘,             @command= @sql,             @database_name=@dbname,             @flags=0    IF (@@ERROR <> 0 OR @ReturnCode <> 0) GOTO QuitWithRollback    EXEC @ReturnCode = msdb.dbo.sp_update_job @job_id = @jobId, @start_step_id = 1    IF (@@ERROR <> 0 OR @ReturnCode <> 0) GOTO QuitWithRollback        --创建调度    declare @ftype int,@fstype int,@ffactor int    select @ftype=case @freqtype when ‘day‘ then 4                                            when ‘week‘ then 8                                            when ‘month‘ then 16 end            ,@fstype=case @fsinterval when 1 then 0 else 8 end    if @fsinterval<>1 set @time=0    set @ffactor=case @freqtype when ‘day‘ then 0 else 1 end        EXEC msdb..sp_add_jobschedule @job_name=@jobname,         @name = @jobname,        @freq_type=@ftype ,                                                @freq_interval=1,                                               @freq_subday_type=@fstype,                               @freq_subday_interval=@fsinterval,                @freq_recurrence_factor=@ffactor,        @active_start_time=@time                                     IF (@@ERROR <> 0 OR @ReturnCode <> 0) GOTO QuitWithRollback    EXEC @ReturnCode = msdb.dbo.sp_add_jobserver @job_id = @jobId, @server_name = N‘(local)‘    IF (@@ERROR <> 0 OR @ReturnCode <> 0) GOTO QuitWithRollback    COMMIT TRANSACTION    GOTO EndSave    QuitWithRollback:        IF (@@TRANCOUNT > 0) ROLLBACK TRANSACTION    EndSave:ENDGO

GOIF EXISTS(SELECT 1 FROM sysobjects WHERE id=OBJECT_ID(‘usp_p_delDBLog‘))BEGIN    DROP PROC dbo.usp_p_delDBLogENDGOCREATE PROC usp_p_delDBLog(    @DriveLimit AS BIGINT,    @DBLogSise AS INT =0)/**    功能：收缩当前数据库日志文件*    参数  @DriveLimit:当前数据库所在磁盘空间到达多少的时候进行收缩数据库  MB*          @DBLogSise：日志文件收缩至多少M 默认收缩到最小*/AS BEGIN    IF @DBLogSise<0 OR @DriveLimit<0    BEGIN        RETURN    END        --当前数据库所在磁盘    DECLARE @Drive AS VARCHAR(10)    DECLARE @Available AS BIGINT    SELECT TOP 1  @Drive=SUBSTRING(filename,1,1)  from   sysfiles    CREATE TABLE #TempFile(        Drive VARCHAR(10),--磁盘        Available BIGINT --可用大小MB    )    INSERT INTO #TempFile(Drive,Available)    exec master..xp_fixeddrives    --查询当前数据库所在磁盘剩余空间大小    SELECT @Available=Available FROM #TempFile    WHERE Drive=@Drive    --符合条件则进行收缩日志文件    IF @Available<=@DriveLimit    BEGIN            --查询出数据库对应的日志文件名称        DECLARE @strDBName AS NVARCHAR(500)        DECLARE @strLogName AS NVARCHAR(500)        DECLARE @strSQL AS VARCHAR(1000)                SELECT             @strLogName=B.name,            @strDBName=A.name        FROM master.sys.databases AS A        INNER JOIN sys.master_files AS B        ON A.database_id = B.database_id        WHERE A.database_id=DB_ID()                     SET @strSQL=‘        --设置数据库恢复模式为简单        ALTER DATABASE [‘+@strDBName+‘] SET RECOVERY SIMPLE;        --收缩日志文件        DBCC SHRINKFILE (‘‘‘+@strLogName+‘‘‘ , ‘+CONVERT(VARCHAR(20),@DBLogSise)+‘);        --恢复数据库还原模式为完整        ALTER DATABASE [‘+@strDBName+‘] SET RECOVERY FULL ‘        exec(@strSQL)        END        DROP TABLE #TempFileENDGO

    --当前数据库所在磁盘    DECLARE @Drive AS VARCHAR(10)    DECLARE @Available AS BIGINT    SELECT TOP 1  @Drive=SUBSTRING(filename,1,1)  from   sysfiles    CREATE TABLE #TempFile(        Drive VARCHAR(10),--磁盘        Available BIGINT --可用大小MB    )    INSERT INTO #TempFile(Drive,Available)    exec master..xp_fixeddrives    --查询当前数据库所在磁盘剩余空间大小    SELECT @Available=Available FROM #TempFile    WHERE Drive=@Drive

--添加作业--作业每天间隔两小时执行一次--执行条件为磁盘空间不足 5000MB，即@DriveLimit=5000 可自行配置DECLARE @@jobname AS VARCHAR(1000)SELECT @@jobname=DB_NAME()+‘_自动清理当前数据库日志文件‘EXEC dbo.usp_p_CreateJob @jobname = @@jobname, -- varchar(100)    @sql = ‘EXEC usp_p_delDBLog @DriveLimit=5000,@DBLogSise=0‘, -- varchar(max)    @freqtype = ‘day‘, -- varchar(6)    @fsinterval = 2, -- int    @time = 235959, -- int    @description = ‘自动清理当前数据库日志文件‘ -- varchar(1000)