仅返回错误ID状态的最新行

Question

我需要一些帮助，试图找到正确的命令，每个bug号码只返回一个rown。以下代码查询错误历史记录表，并返回错误的所有条目。但我想要的只是最新的价值。

 select bughist.id,bughist.user_id,bughist.bug_id,bughist.field_name,
   case 
   when bughist.old_value = 10 then 'New'
   when bughist.old_value = 20 then 'Feedback' 

    when bughist.old_value = 40 then 'Confirmed' 
    when bughist.old_value = 50 then 'Assigned' 
    when bughist.old_value = 55 then 'Deferred' 
    when bughist.old_value = 60 then 'RFT' 
    when bughist.old_value = 80 then 'Resolved'
    when bughist.old_value = 90 then 'Released' 
    when bughist.old_value = 95 then 'Rejects' 
    Else NULL End as 'Old_value', 
    case when bughist.new_value = 10 then 'New'
    when bughist.new_value = 20 then 'Feedback'
    when bughist.new_value = 40 then 'Confirmed' 
    when bughist.new_value = 50 then 'Assigned' 
    when bughist.new_value = 55 then 'Deferred' 
    when bughist.new_value = 60 then 'RFT' 
    when bughist.new_value = 80 then 'Resolved'
    when bughist.new_value = 90 then 'Released' 
    when bughist.new_value = 95 then 'Rejects' 
    Else NULL End as 'New_value',
    bughist.type,from_unixtime(bughist.date_modified) as 'moddate' from bug_history_table bughist
    left join bugtracker.bug_table bug 
    on bughist.bug_id = bug.id 
    where field_name = 'status'  and bug.project_id in (23,24,25,26,27,28,29,30,31)
    group by bughist.date_modified
    order by bughist.bug_id, bughist.id

出来的是

但我不想要所有这些行。正如你可以从照片上的那个人看到的那样。这是对该特定错误的最后更新。所以我想用这个查询显示的只是每个已知错误ID的最后更新行。我已经尝试过MAX但没有得到任何快乐'