SQL Server 2008 R2 清除日誌

在SQL SERVER 2008 R2上測試通過，其它版本請自行測試，使用時無需要切換到對應的數據庫上操作

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--創建 數據庫日誌清空
--編寫 時間 2019-5-9 
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--調用 Exec ShrinkLogBy2008R2 數據庫名稱

If Exists (select 1 from sysobjects where name = 'ShrinkLogBy2008R2' and type = 'P')
   Drop PROCEDURE ShrinkLogBy2008R2
Go
CREATE Procedure ShrinkLogBy2008R2(
	@DbName Varchar(100)
)
AS 
Begin 

  Declare @FrontSize Int --收縮前大小
  Declare @AfterSize Int --收縮後大小

  --1.獲取當前模式
  Declare @RecoveryModel Varchar(20)
  Select @RecoveryModel = recovery_model_desc From sys.databases where name = @DbName
  
  --2.修改爲Simple模式
  if @RecoveryModel = 'FULL'
  Begin
     Exec ('ALTER DATABASE ' + @DbName +  ' Set Recovery Simple')
  End
  
  --3.獲取日誌文件名
  Declare @Sql NVARCHAR(200),@LogFileName Varchar(20)
  Set @Sql = 'use ' + @DbName + ' select @LogFile = name,@Size = size from sys.database_files where type_desc = ''LOG'''
  Exec Sp_ExecuteSql @Sql,N'@LogFile As VARCHAR(20) OUTPUT,@Size As Int OutPut',@LogFile = @LogFileName OUTPUT,@Size = @FrontSize OUTPUT
  Print ('日誌文件:' + @LogFileName)
    
  --4.收縮日誌文件大小(單位是M)
  Exec('use ' + @DbName + ' DBCC SHRINKFILE (' + @LogFileName + ', 0)')
  
  --5.修改爲 FULL 模式
  Exec ('ALTER DATABASE ' + @DbName +  ' Set Recovery FULL')
  
  --6.收縮後大小
  Set @Sql = 'use ' + @DbName + ' select @Size = size from sys.database_files where type_desc = ''LOG'''
  Exec Sp_ExecuteSql @Sql,N' @Size As VARCHAR(20) OUTPUT',@Size = @AfterSize OUTPUT
  
  --7.返回結果
  Select @DbName 數據庫,@LogFileName 日誌文件,@FrontSize 收縮前大小,@AfterSize 收縮後大小
  
End