ABORT ON回滚事务？
根据SET XACT_ABORT ON的联机丛书文档，我得到的印象是，如果T-SQL语句引发运行时错误，则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，则整个事务将终止并回滚。
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
我也有这样的印象：如果出现错误， SET XACT_ABORT ON终止批处理：
SET XACT_ABORT ON指示SQL Server在发生运行时错误时回滚整个事务并中止批处理。
这听起来很方便。 我怎么能让它做到这一点？
当严重性级别大于或等于16时，SQL Server仅回滚事务。
看例子：
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
请参阅上的Microsoft错误消息级别
http://msdn.microsoft.com/en-us/library/aa937483(v=sql.80).aspx
当您在try catch语句中使用xact abort时，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