如何使SET XACT_ABORT ON回滚事务？

Question

基于Books Online documentation of SET XACT_ABORT ON，我得到的印象是，如果T-SQL语句引发运行时错误，整个事务将终止并回滚：

备注

当SET XACT_ABORT为ON时，如果Transact-SQL语句引发运行时错误，则终止并回滚整个事务。

在SQL Server 2008 R2中测试：

SET XACT_ABORT ON;
BEGIN TRANSACTION;
PRINT 'TranCount befor an error = '+CAST(@@Trancount AS varchar(50))

DROP TABLE QuertyAsdf

PRINT 'TranCount after an error = '+CAST(@@Trancount AS varchar(50))

给出输出：

TranCount befor an error = 1
Msg 3701, Level 11, State 5, Line 6
Cannot drop the table 'QwertyAsdf', because it does not exist or you do not have permission.
TranCount after an error = 1

我的印象也是SET XACT_ABORT ON terminates the batch if there's an error：

SET XACT_ABORT ON指示SQL Server回滚整个事务，并在发生运行时错误时中止批处理。

这听起来很方便。我怎么能这样做呢？

Answer 1

当严重性级别更高或等于16时，SQL Server仅回滚事务。

见例子：

Msg 544, Level 16, State 1, Line 1
Cannot insert explicit value for identity column in table 'ORC_ORCAMENTO' whenIDENTITY_INSERT is set to OFF.

在SQL Server 2008 R2上测试

SET XACT_ABORT ON;
BEGIN TRANSACTION;
PRINT 'TranCount befor an error = '+CAST(@@Trancount AS varchar(50))
insert into ORC_ORCAMENTO (ORCID, ORCNOME, ORCATIVO) VALUES (1, 'TESTE_ALEXP', 0);
PRINT 'TranCount after an error = '+CAST(@@Trancount AS varchar(50))

返回

TranCount befor an error = 1
Msg 544, Level 16, State 1, Line 5
Cannot insert explicit value for identity column in table 'ORC_ORCAMENTO' when IDENTITY_INSERT is set to OFF.
TranCount after an error = 0

请参阅Microsoft错误消息级别

https://docs.microsoft.com/en-us/sql/relational-databases/errors-events/database-engine-events-and-errors

Answer 2

当您使用xact abort on时，在try catch语句中，您可以手动引发错误以使事务回滚。

set xact_abort on;

begin try
    ...dml statements here....

if conditions here...
    raiseerror(....);

end try
begin catch

end catch