sql使用自连接去重复查询
查询公司与公司最新刷新的一条信息
select t1.userid,t1.id,t1.title,t1.RegType,t1.Salary,t1.SubjectID,t1.RefreshTime,t2.name,t2.logo,t2.[address],t2.CreateTime from info t1 inner join companyinfo t2 on t1.userid=t2.id where t1.id in ( select top 1 info.id from info where userid = t1.userid order by refreshtime desc ) and t1.userid in ( select distinct userid from PackageRecord where PackagePid=1 and getdate()<endtime )