SQL Server ->> THROW字句对比RAISERROR子句

SQL Server 2012开始引入了THROW字句用于替代从SQL Server开始沿用至今的RAISERROR。既然作用相同，都是在TRY... CATCH代码块后不抓错误然后抛出错误，它们之间的差异是什么？

RAISERROR statement	THROW statement
If a msg_id is passed to RAISERROR, the ID must be defined in sys.messages.	The error_number parameter does not have to be defined in sys.messages.
The msg_str parameter can contain printf formatting styles.	The message parameter does not accept printf style formatting.
The severity parameter specifies the severity of the exception.	There is no severity parameter. The exception severity is always set to 16.

上表列出了它们的差异

THROW对比RAISERROR最大的优势在于，我们不再需要在CATCH代码块里面捕捉到ERROR_MESSAGE()， ERROR_STATE()等几个系统函数的值然后赋值给变量，只需要一个THROW语句就可以完成原本RAISERROR需要赋值变量再通过参数传入抛出异常的过程。而且对于错误行的捕捉也是直接指向错误行，而不是像RAISERROR那样是RAISERROR语句发生时的代码行。而且THROW还是可以像RAISERROR一样可以传参，效果和RAISERROR是一样的。

总结就是RAISERROR可以做的THROW都可以做到，而THROW还可以节省RAISERROR原本需要多个步骤完成的事情。而微软也是推荐用THROW去代替RAISERROR。

-- Using THROW - 1
BEGIN TRY
 SELECT 1/0 as DivideByZero
END TRY
BEGIN CATCH
 THROW;
END CATCH
GO

结果

(0 row(s) affected)
Msg 8134, Level 16, State 1, Line 6
Divide by zero error encountered.

而如果用RAISERROR

USE [JerryDB]
GO

-- Using RAISERROR()
DECLARE 
 @ERR_MSG AS NVARCHAR(4000)
 ,@ERR_SEV AS SMALLINT
 ,@ERR_STA AS SMALLINT
 
BEGIN TRY
 SELECT 1/0 as DivideByZero
END TRY
BEGIN CATCH
 SELECT @ERR_MSG = ERROR_MESSAGE(),
 @ERR_SEV =ERROR_SEVERITY(),
 @ERR_STA = ERROR_STATE()
 SET @ERR_MSG= 'Error occurred while retrieving the data from database: ' + @ERR_MSG
 
 RAISERROR (@ERR_MSG, @ERR_SEV, @ERR_STA) WITH NOWAIT
END CATCH
GO

结果

(0 row(s) affected)
Msg 50000, Level 16, State 1, Line 19
Error occurred while retrieving the data from database: Divide by zero error encountered.

参考：

New THROW statement in SQL Server 2012 (vs RAISERROR)