Question

我已成功配置并能够通过调用msdb.dbo.sp_send_dbmail存储过程在SQL Server 2008 R2上使用“数据库邮件”发送电子邮件。我可以通过将它放在try-catch块中来捕获触发器中的查询失败。

但我需要做的是，当触发器无法执行查询时发送电子邮件。但是我无法在catch块中执行上面的存储过程。它给了我以下错误。

Msg 3930, Level 16, State 1, Procedure sp_send_dbmail, Line 64
The current transaction cannot be committed and cannot support operations that write to the log file. Roll back the transaction.
The statement has been terminated.

还有其他方法可以在触发失败时发送电子邮件吗？或者如何解决这个问题？

Answer 1

触发器失败将始终导致事务回滚，因此无法执行任何事务操作，如调用sp_send_dbmail。一个技巧是利用自定义探查器跟踪事件，因为它们是在独立事务上发送的：

create queue q;
create service sq 
    on queue q
    ([http://schemas.microsoft.com/SQL/Notifications/PostEventNotification]);
go

create event notification trace_user_0
    on server 
    for TRC_USER_CONFIGURABLE
    to service N'sq', N'current database';
go


create procedure usp_sq
as
begin

    declare @dh uniqueidentifier, 
        @mt sysname, 
        @mb varbinary(max),
        @mx xml;

    begin transaction

    receive top(1) 
        @dh = conversation_handle,
        @mt = message_type_name,
        @mb = message_body
        from q;

    if @mt = N'http://schemas.microsoft.com/SQL/Notifications/EventNotification'
    begin
        set @mx = cast(@mb as xml);

        declare @eventText nvarchar(4000);
        select @eventText = @mx.value (N'(//EVENT_INSTANCE/TextData)[1]', N'nvarchar(4000)');

        exec sp_send_dbmail @subject = 'Error in trigger', @body = @eventText;

    end
    else if @mt in (
        N'http://schemas.microsoft.com/SQL/ServiceBroker/Error', 
        N'http://schemas.microsoft.com/SQL/ServiceBroker/EndDialog')
    begin
        end conversation @dh;
    end

    commit

end
go

alter queue q with activation (
    status = on,
    max_queue_readers = 1,
    execute as = 'owner',
    procedure_name = 'usp_sq');
go

create table MyTable (a int);
go

create trigger MyTrigger 
    on MyTable 
    after insert
as
begin try
    if rand() > 0.5
        raiserror (N'Something horrible happend in this trigger!', 16,1);
end try
begin catch
    declare @error_message nvarchar(256) = cast(error_message() as nvarchar(256));
    exec sp_trace_generateevent 82, @error_message;
end catch
go

insert into MyTable (a) values (1);
insert into MyTable (a) values (2);
insert into MyTable (a) values (3);
insert into MyTable (a) values (4);
insert into MyTable (a) values (5);
insert into MyTable (a) values (6);
go

发送触发失败的电子邮件

1 个答案: