SQL - 使用 Union All 并添加重复项答案

【问题标题】：SQL - Using Union All and add duplicatesSQL - 使用 Union All 并添加重复项
【发布时间】：2016-11-14 02:17:15
【问题描述】：

我正在使用 Union All 进行查询，并且我想确保将重复的行添加到结果查询中。使用 Union All 时，无法正确添加重复行。在谷歌搜索“sql union with duplicates”时，它指出：“Union 将删除重复项。Union All 不会。您在查询的第一部分中还没有重复项（可能由左连接生成）。据我了解，UNION 它不会添加到结果集中已经存在的行中，但不会删除第一个数据集中已经存在的重复项。”就我而言，我确实想添加已经在其中的结果集行。我该怎么做？

这是我的查询：

SELECT player_name_fkey, school_name_fkey, score_simple, sum(score_simple) over (partition by player_name_fkey) as sum_scores

FROM (

    SELECT player_name_fkey, school_name_fkey, SUM(score) as score_simple 

        FROM simple LEFT JOIN players on players.name=simple.player_name_fkey 

        WHERE category='Cadet' AND gender='Féminin' GROUP BY player_name_fkey, school_name_fkey

    UNION ALL

        SELECT player_name_fkey, school_name_fkey, SUM(score) as score_simple

        FROM double LEFT JOIN players on players.name=double.player_name_fkey 

        WHERE category='Cadet' AND gender='Féminin' GROUP BY player_name_fkey, school_name_fkey) t1

GROUP BY player_name_fkey, school_name_fkey, score_simple

提前感谢您的帮助！

【问题讨论】：

尝试删除末尾的GROUP BY 子句。
像魅力一样工作，谢谢！

标签： sql postgresql

【解决方案1】：

正如 Felix Pamittan 所说，最后删除 GROUP BY 子句解决了我的问题。

SELECT player_name_fkey, school_name_fkey, score_simple, sum(score_simple) over (partition by player_name_fkey) as sum_scores

FROM (

    SELECT player_name_fkey, school_name_fkey, SUM(score) as score_simple 

    FROM simple LEFT JOIN players on players.name=simple.player_name_fkey 

    WHERE category='Cadet' AND gender='Féminin' GROUP BY player_name_fkey, school_name_fkey

UNION ALL

    SELECT player_name_fkey, school_name_fkey, SUM(score) as score_simple

    FROM double LEFT JOIN players on players.name=double.player_name_fkey 

    WHERE category='Cadet' AND gender='Féminin' GROUP BY player_name_fkey, school_name_fkey) t1

【讨论】：