避免在PostgreSQL中基于多个列的重复条目

我正在尝试从以下结果集中删除重复项：

ID  Name    missionID   teamID  eventTimestamp  
25  C   1000415147500265653 1   02-11-2014 14:04  
25  C   1000415147500265653 1   02-11-2014 14:04  
25  C   1000415147500265653 1   02-11-2014 14:04  
25  C   1000415147500265653 1   02-11-2014 14:04  
25  C   1000415147500265653 2   02-11-2014 14:06  
25  C   1000415147500265653 2   02-11-2014 14:06  
25  C   1000415147500265653 2   02-11-2014 14:06  
25  C   1000415147500265653 2   02-11-2014 14:07  
25  C   1000415147500265653 2   02-11-2014 14:07  
25  C   1000415147500265653 1   02-11-2014 14:08  
25  C   1000415147500265653 1   02-11-2014 14:08  

对于targetID、targetName、missionID、teamID和eventTimestamp的每个组合，我只需要一个条目。因此，我希望结果集如下所示，而不是上面所示：

targetID    targetName  missionID   teamID  eventTimestamp  
25  C   1000415147500265653 1   02-11-2014 14:04  
25  C   1000415147500265653 2   02-11-2014 14:06  
25  C   1000415147500265653 2   02-11-2014 14:07  
25  C   1000415147500265653 1   02-11-2014 14:08  

如你所见。可能还有其他条目具有相同的targetID、targetName、missionID、teamID组合，但具有不同的时间戳-我需要保留这些条目，因此我不能只在这上面运行max或min date。我曾尝试使用distinct、ranking和group by，但似乎没有任何效果，我不断收到重复条目。如果我在日期上使用max或min，那么每个targetID、targetName、missionID、teamID只能获得一个条目，而这不是我想要的

我的原始查询仅用于获取重复结果集，如下所示：

select targetID, targetName, missionID, teamID, eventTimestamp from (
select a.characterID, a.targetID, a.targetName, a.missionID, b.teamID as teamID, a.eventTimestamp from events_live a
left join (
select distinct characterID, teamID from events_live where eventName = 'missionStarted' or eventName = 'characterCreated') b on a.characterID = b.characterID 

where eventName ='missionObjective' and a.eventTimestamp > '2014-10-31' and a.eventTimestamp < '2014-11-07' and objectiveName = 'Capture' and (targetID ='25' or targetID='26' or targetID ='27' or targetID = '28' or targetID = '29') and b.teamID is not null
order by missionID, targetID, eventTimestamp
)t1

order by missionID, targetID, eventTimestamp

我试着在原始的基础上，通过targetID、targetName、missionID、teamID、eventTimestamp对group进行另一次选择，但仍然得到了重复的结果。我已尝试在eventTimestamp上运行distinct，但它仍然无法满足我的需求

SELECT targetID, targetName, missionID, teamID, date_trunc('minute',eventTimestamp ) AS eventTimestamp
FROM (
    SELECT a.characterID, a.targetID, a.targetName, a.missionID, b.teamID as teamID, a.eventTimestamp 
    FROM events_live a
    LEFT JOIN (
        SELECT distinct characterID, teamID from events_live 
        WHERE eventName = 'missionStarted' 
        OR eventName = 'characterCreated') b 
    ON a.characterID = b.characterID     
    WHERE eventName ='missionObjective' 
    AND a.eventTimestamp > '2014-10-31' 
    AND a.eventTimestamp < '2014-11-07' 
    AND objectiveName = 'Capture' 
    AND (
        targetID ='25' 
        OR targetID='26' 
        OR targetID ='27' 
        OR targetID = '28' 
        OR targetID = '29') 
    AND b.teamID IS NOT NULL
    ORDER BY missionID, targetID, eventTimestamp) t1
GROUP BY targetID, targetName, missionID, teamID, eventTimestamp    
ORDER BY missionID, targetID, eventTimestamp

---

编辑：date_trunc'minute'，eventTimestamp应该可以做到这一点

Ok，但它是一个包含连接的大型查询，甚至可以获得重复的结果集：更新我的答案，使用上面的查询，您不会得到正确的结果？我仍然会得到重复的结果：-@LeneJungKjær您是对的。博士。说明：当时间戳值存储为8字节整数（当前为默认值）时，可在整个时间范围内获得微秒精度values@LeneJungKjær更新了我的答案