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sql server 2005中新增加的try catch学习


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  sql server 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
  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'
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