SQL去重的3种实用方法总结

select distinct UserResult from Table1

select min(UserName)UserName,min(UserSex)UserSex,min(UserSubject)UserSubject,min(UserResult)UserResult from Table1
group by UserResult

select *from
(
--查询出重复行
select *,row_number() over (partition by UserResult order by UserResult desc)num from Table1
)A
where A.num=1

--程序1：要解决的问题
select a.*
  from AShareEarningEst a
 where a.S_INFO_WINDCODE in ('000650.SZ')
   and a.REPORTING_PERIOD = 20181231
order by a.RESEARCH_INST_NAME,a.EST_DT

--程序2：最终解决问题的程序
select b.*
from (select row_number() over(partition by a.RESEARCH_INST_NAME,
              a.ANALYST_NAME order by est_dt desc) as rn,
             --根据RESEARCH_INST_NAME（证券公司名称）和ANALYST_NAME（研究员名字）进行分类，
             --同时根据est_dt（估计日期）倒序排序，即最新日期排在同一分类的上方，此时构建出rn为
             a.*
        from wdzx.AShareEarningEst a
       where a.S_INFO_WINDCODE in ('000650.SZ') --, '000951.SZ', '600006.SH', '600166.SH')
         and a.REPORTING_PERIOD = 20181231) b --将分类后的程序构成表b。可以先运行b的程序观察结果
       where b.rn = 1--运用表b的结果进行子查询，rn=1即为所需结果