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sql server 2005中新增加的try catch学习

浏览:113日期:2023-10-30 10:45:29

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 TRYBEGIN 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 TRYBEGIN CATCH PRINT 'Error Detected'END CATCHPRINT '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 TryBegin 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 CatchEnd Catch另外,SQL SERVER 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 TRYBEGIN 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_MessageEND CATCHPRINT 'Command after TRY/CATCH blocks'最后输出Error DetectedErr_Num Err_Sev Err_State Err_Proc;;Err_Line; Err_Msg------- ------- --------- -------------------- --------- --------------------------------8134;;;;;16; 1 NULL 4;;;;;Divide by zero error encountered.

标签: Sql Server 数据库