select * from tmailsystem where fdate<@date1
select * from tmailreference where fguid in (select fguid from tmailsystem where fdate<@date1)
select * from tmailcontent where fguid in (select fguid from tmailsystem where fdate<@date1)
可以么?其中有一个测试的邮件只有一个附件,查到的结果是2条,有个索引0和1