Question

我创建了此代码以从我们的数据库中提取票证，并且还提取最后一个票据注释日期和最后一个票证用户。除非两个人（或更多）在最后一个日期创建了一个音符（无论时差），否则它将为每个票证创建多行。我该如何解决？这是代码：

Select distinct t.ticketID,
  t.OpenDate, 
  c.categoryname, 
  s.statusname, 
  p.priorityname, 
  u.firstname, 
  u.lastname, 
  tu.firstname as 'tech_firstname', 
  tu.lastname as 'tech_lastname',
  ltn.maxdate as 'last date',
  ltu.firstname + ' ' + ltu.lastname as 'Last User'

  from ticket t
        left join category c on t.categoryid = c.categoryid
        left join [status] s on t.statusid = s.statusid
        left join [priority] p on t.priorityid = p.priorityid
        left join [user] u on t.userid = u.userid
        left join [user] tu on t.technicianid = tu.userid
        left join ticketnote tn on t.ticketid = tn.ticketid
        inner join (
            Select Max(TicketNoteDate) as MaxDate, max(cast(ticketnotedate as time)) as MaxTime, ticketid, userid
            From ticketNote
            group by ticketid, userid) ltn on tn.ticketid = ltn.ticketid and tn.ticketnotedate = ltn.maxdate and cast(tn.ticketnotedate as time) = ltn.maxtime
        left join [user] ltu on ltn.userid = ltu.userid

  where t.statusid = 1
  and t.LocationID = 1

  order by t.ticketid

Answer 1

根据评论中的建议，在您的子查询中使用row_number获取maximum值

      SELECT row_number() over
            (partition by tiketid, userid 
             order by  TicketNoteDate desc ) as rn, 
             ticketid, 
             userid, 
             ticketnotedate

然后join，外部查询条件为rn=1

Answer 2

我重写了它获取所有票证的最大日期，然后查找具有该最大日期的所有票证，并按时间顺序排序并获得第一行，然后检索该条目的额外数据（如用户）。我无法测试这个，但是这里......

Select distinct t.ticketID,
  t.OpenDate, 
  c.categoryname, 
  s.statusname, 
  p.priorityname, 
  u.firstname, 
  u.lastname, 
  tu.firstname as 'tech_firstname', 
  tu.lastname as 'tech_lastname',
  ltn.maxdate as 'last date',
  ltu.firstname + ' ' + ltu.lastname as 'Last User'

  from ticket t
        left join category c on t.categoryid = c.categoryid
        left join [status] s on t.statusid = s.statusid
        left join [priority] p on t.priorityid = p.priorityid
        left join [user] u on t.userid = u.userid
        left join [user] tu on t.technicianid = tu.userid       
        inner join (
            select maxdate, maxtime, ticketid, userid, rownum from (
                select maxdate, maxtime, ticketid, userid, row_number() over (order by maxdate desc, maxtime desc) as rownum
                from ticketnote tn,
                (Select Max(TicketNoteDate) as MaxDate
                From ticketNote) mx
                where mx.maxdate = tn.ticketnotedate 
                ) x where x.rownum = 1
        ) ltn
        left join [user] ltu on ltn.userid = ltu.userid

  where t.statusid = 1
  and t.LocationID = 1

  order by t.ticketid

仅在SQL Server中获取最新的日期时间

2 个答案: