最新数据

Question

我有一个看起来像这样的架构。

使用录音表，查询数据库中每个entityid / accid / month组合的最新数据（Main Table是主表）

Answer 1

使用my_vector_1<-c(1,3,5,7,9,11,2,4,6,8,10,12,3,5,7,9,11,13) my_matrix_1<-matrix(data=my_vector_1, nrow=6, ncol=3) colnames(my_matrix_1)<-c(paste0("Age", 2000:2002)) rownames(my_matrix_1)<-c(paste0("Participant", 1:6)) my_data_1<-data.frame(my_matrix_1)

row_number()

Answer 2

使用row_number()

  select * from 
    (
    select m.*, row_number() over(partition by acctid,entid,month order by timestamp desc) rn
    from maintable m join racordings r on m.logid=r.logid
    ) a where a.rn=1

Answer 3

这是您的查询。

select * from 
    (select m.*, r.*, e.*, a.*, row_number() over(partition by a.AcctID, e.EntID, Month order by r.TimeStamp desc) row_num
        from maintable m 
        inner join racordings r on m.LogID = r.LogID
        inner join Entities e on e.EntID = m.EntID
        inner join AccInfo a on a.AcctID = m.AcctID
    ) t1 
where t1.row_num = 1