Sql Server存储过程中加入Try Catch,并向客户端返回友好信息

create proc P_Insert_New_BookTitle_2K5
(@TitleName nvarchar(128),
 @Price money,
 @au_fname nvarchar(32),
 @au_name nvarchar(64),
 @CommissionRating int)
as
declare @err int,
        @tablename sysname,
        @errormessage nvarchar(2000)

BEGIN TRY

    begin transaction
    select @errormessage = 'insert into Titles table failed',
         @tablename = 'Titles'
    insert dbo.Titles (TitleName, Price)
    values (@TitleName, @Price)

    select @errormessage = 'insert into Authors table failed',
         @tablename = 'Authors'
    insert dbo.Authors  (au_fname, au_lname, TitleID,CommissionRating)
    values (@au_fname, @au_fname, @@IDENTITY, @CommissionRating)
    commit transaction
END TRY

BEGIN CATCH
    
    ROLLBACK TRANSACTION

    -- Log the error
    insert dbo.Application_Error_Log (UserName, tableName,     
            errorNumber, errorSeverity, errorState, errorMessage)
    values (suser_sname(), @tableName, ERROR_NUMBER(),  
            ERROR_SEVERITY(), ERROR_STATE(), ERROR_MESSAGE())  

    RAISERROR (@errormessage, 16,1)

--返回用户定义的错误信息并设系统标志，记录发生错误。

END CATCH