sql server 2005中新增加的try catch学习

核心提示：sql server(WINDOWS平台上强大的数据库平台) 2005中新增加的try catch，可以很容易捕捉异常了，sql server 2005中新增加的try catch学习，今天大概学习看了下，归纳下要点如下基本用法BEGIN TRY { sql_statement | statement_b

sql server(WINDOWS平台上强大的数据库平台) 2005中新增加的try catch，可以很容易捕捉异常了，今天大概学习看了下，归纳下要点如下

基本用法BEGIN TRY
　　 {  sql_statement |
 statement_block  }
END TRY
BEGIN CATCH
　　 {  sql_statement |
 statement_block }
END CATCH
，和普通语言的异常处理用法差不多，但要注意的是，sql server(WINDOWS平台上强大的数据库平台)只捕捉那些不是严重的异常，当比如数据库不能连接等这类异常时，是不能捕捉的一个例子：BEGIN TRY
  DECLARE @X INT
  -- Divide by zero to generate Error
  SET @X = 1/0
  PRINT 'Command after error in TRY block'
END TRY
BEGIN CATCH
  PRINT 'Error Detected'
END CATCH
PRINT 'Command after TRY/CATCH blocks' 
另外try catch可以嵌套Begin TRY
  delete from GrandParent where Name = 'John Smith'
  print 'GrandParent deleted successfully'
End Try
Begin Catch
　 Print 'Error Deleting GrandParent Record'
　 Begin Try
　　 delete from Parent where GrandParentID =
　　 (select distinct ID from GrandParent where Name = 'John Smith')
　　 Print 'Parent Deleted Successfully'
　 End Try
　 Begin Catch
　　 print 'Error Deleting Parent'
　　 Begin Try
　　　 delete from child where ParentId =
　　 (select distinct ID from Parent where GrandParentID =
　　 (select distinct ID from GrandParent where Name = 'John Smith'))
　　　 print 'Child Deleted Successfully'
　　 End Try
　　 Begin Catch
　　　 Print 'Error Deleting Child'
　　 End Catch
　 End Catch
 End Catch
另外，sql server(WINDOWS平台上强大的数据库平台) 2005在异常机制中，提供了error类的方法方便调试，现摘抄如下，比较简单，不予以解释ERROR_NUMBER(): Returns a number associated with the error.ERROR_SEVERITY(): Returns the severity of the error.ERROR_STATE(): Returns the error state number associated with the error.ERROR_PROCEDURE(): Returns the name of the stored procedure or trigger in which the error occurred.ERROR_LINE(): Returns the line number inside the failing routine that caused the error. ERROR_MESSAGE(): Returns the complete text of the error message. The text includes the values supplied for any substitutable parameters, such as lengths, object names, or times. 最后举例子如下，使用了error类的方法BEGIN TRY
  DECLARE @X INT
  -- Divide by zero to generate Error
  SET @X = 1/0
  PRINT 'Command after error in TRY block'
END TRY
BEGIN CATCH
  PRINT 'Error Detected'
  SELECT ERROR_NUMBER() ERNumber,
　　　　 ERROR_SEVERITY() Error_Severity,
　　　　 ERROR_STATE() Error_State,
　　　　 ERROR_PROCEDURE() Error_Procedure,
　　　　 ERROR_LINE() Error_Line,
　　　　 ERROR_MESSAGE() Error_Message
END CATCH
PRINT 'Command after TRY/CATCH blocks'
最后输出Error Detected
Err_Num Err_Sev Err_State Err_Proc　　　　　　 Err_Line  Err_Msg
------- ------- --------- -------------------- --------- --------------------------------
8134　　　  16　　　　  1 NULL　　　　　　　　 4　　　  Divide by zero error encountered.