Question

我正在使用postresql，但我真的很擅长构建SQL查询。我有这个查询，它的工作原理：

SELECT handhistories FROM handhistories 
JOIN pokerhands using (pokerhand_id)  
JOIN gametypes using (gametype_id)
RIGHT OUTER JOIN playerhandscashkeycolumns using (pokerhand_id)
     WHERE pokerhands.site_id=0  
     AND pokerhands.numberofplayers>=5 and  pokerhands.numberofplayers<=7
     AND (bigblind = 2 OR bigblind = 4 )
     AND player_id in 
        (SELECT player_id FROM playerhandscashkeycolumns GROUP BY player_id
         HAVING AVG(case didvpip when true then 100::real else 0 end) <= 20 )

但我也想限制最后一个“拥有”，所以它会是这样的，但是当然它不起作用。

SELECT handhistories FROM handhistories 
JOIN pokerhands using (pokerhand_id)  
JOIN gametypes using (gametype_id)
RIGHT OUTER JOIN playerhandscashkeycolumns using (pokerhand_id)
       WHERE pokerhands.site_id=0  
       AND pokerhands.numberofplayers>=5 and  pokerhands.numberofplayers<=7
       AND (bigblind = 2 OR bigblind = 4 )
       AND player_id in 
        (SELECT player_id FROM playerhandscashkeycolumns GROUP BY player_id
         HAVING AVG(case didvpip when true then 100::real else 0 end) <= 20
         AND  HAVING AVG(case didvpip when true then 100::real else 0 end) > 10 )

如何“保存”之后的值，所以我也可以从底部比较它？谢谢大家。

Answer 1

BETWEEN会为你工作吗？

HAVING AVG(case didvpip when true then 100::real else 0 end) BETWEEN 10 AND 20

（顺便说一句：丑陋的SQL语法，重用AND关键字）

更新：还可用于简化查询的其余部分：

AND pokerhands.numberofplayers BETWEEN 5 AND 7
AND bigblind IN ( 2, 4 )

Answer 2

这主要是 @wildplasser 已经指出的内容 ..减去BETWEEN的错误 ..加JOIN而不是IN构造，这在PostgreSQL中通常更快 ..更容易阅读

SELECT handhistories
FROM   handhistories
JOIN   pokerhands USING (pokerhand_id)  
JOIN   gametypes USING (gametype_id)
RIGHT  JOIN playerhandscashkeycolumns USING (pokerhand_id)
JOIN   (
    SELECT player_id
    FROM   playerhandscashkeycolumns
    GROUP  BY player_id
    HAVING avg(CASE WHEN didvpip THEN 100::real ELSE 0 END) >  10
    AND    avg(CASE WHEN didvpip THEN 100::real ELSE 0 END) <= 20
    ) p USING (player_id)
WHERE  pokerhands.site_id = 0  
AND    pokerhands.numberofplayers BETWEEN 5 AND 7
AND    bigblind IN (2,4);

您可以对某些列进行表格限定，例如pokerhands.site_id，而不是其他列，例如handhistories，您可能需要清除它。

PostgreSQL：join + outer-join + sub-select与比较值的问题。

2 个答案: