Progress DB，需要合并两个查询答案

【问题标题】：Progress DB, need to merge two queriesProgress DB，需要合并两个查询
【发布时间】：2012-12-26 06:10:51
【问题描述】：

我有 2 个进度数据库查询，我正在尝试将它们合并到一个语句中，但我遇到了错误。这些查询中的每一个都只返回一个数字，我想将这两个数字相加。要么从头开始进行另一个查询。他们都接受一组“DM1”的价值代码，他们都接受1个“产品”。

查询 1

SELECT SUM(opn3.samt)
    FROM PUB.ord ord3, PUB.opn opn3
    WHERE
    ord3.subsnum = opn3.subsnum
    AND ord3.onum = opn3.onum
    AND ord3.DM1 != ''
    AND ord3.DM1 IN('XCWAJC25','WCWAMO73') 
    AND ord3.prdcde = 'CSC' 
    AND ord3.stat != 16
    AND opn3.samt >= 0
    GROUP BY ord3.DM1, ord3.prdcde

查询 2

SELECT SUM((-1 * opn2.samt) + ord2.samt)
    FROM PUB.ord ord2, PUB.opn opn2
    WHERE
    ord2.subsnum = opn2.subsnum
    AND ord2.onum = opn2.onum
    AND ord2.DM1 != ''
    AND ord2.DM1 IN('XCWAJC25','WCWAMO73') 
    AND ord2.prdcde = 'CSC' 
    AND ord2.stat = 16
    AND opn2.samt < 0
    GROUP BY ord2.DM1, ord2.prdcde

到目前为止的合并尝试...

SELECT SUM(opn3.samt + (SELECT SUM((-1 * opn2.samt) + ord2.samt)
    FROM PUB.ord ord2, PUB.opn opn2
    WHERE
    ord2.subsnum = opn2.subsnum
    AND ord2.onum = opn2.onum
    AND ord2.DM1 != ''
    AND ord2.DM1 = ord3.DM1
    AND ord2.prdcde = ord3.prdcde 
    AND ord2.stat = 16
    AND opn2.samt < 0
    GROUP BY ord2.DM1, ord2.prdcde
)) as foo

    FROM PUB.ord ord3, PUB.opn opn3
    WHERE
    ord3.subsnum = opn3.subsnum
    AND ord3.onum = opn3.onum
    AND ord3.DM1 != ''
    AND ord3.DM1 IN('XCWAJC25','WCWAMO73') 
    AND ord3.prdcde = 'CSC' 
    AND ord3.stat != 16
    AND opn3.samt >= 0
    GROUP BY ord3.DM1, ord3.prdcde

谢谢

【问题讨论】：

标签： sql join group-by aggregate-functions progress-db

【解决方案1】：

我认为这会起作用，尽管有样本数据来验证会很好：

SELECT COALESCE(SUM(a.samt), 0) - COALESCE(SUM(b.samt), 0)
       + COALESCE(SUM(CASE WHEN ord.stat = 16
                                AND b.samt < 0
                           THEN ord.samt END), 0)
FROM PUB.ord ord
LEFT JOIN PUB.opn a
       ON a.subsnum = ord.subsnum
          AND a.onum = ord.onum
          AND a.samt >= 0
          AND ord.stat != 16
LEFT JOIN PUB.opn b
          ON b.subsnum = ord.subsnum
             AND b.onum = ord.onum
             AND b.samt < 0
             AND ord.stat = 16
WHERE ord.DM1 IN('XCWAJC25', 'WCWAMO73') 
      AND ord.prdcde = 'CSC'
GROUP BY ord.DM1

关于查询/东西的注释：

始终明确限定联接，不要使用逗号分隔的FROM 子句
我认为您不需要 ord.DM1 != ''，因为值必须位于特定集合中
将子句放入LEFT JOIN 条件而不是WHERE 子句的效果略有不同；它将条件添加到连接中，而不是过滤。这意味着可以根据左表中的某些内容排除行，无论您是否需要实际行（这就是ord.stat 最终出现在LEFT JOINs 中的原因）。从技术上讲，INNER JOINs 的行为方式相同，但通常不会引起注意，因为排除右表也会排除左表。

【讨论】：

亲爱的上帝，你做到了！天哪，非常感谢这个人。在一个治理荒谬的国家，你让一个脑残的程序员非常高兴！

【解决方案2】：

鉴于各个查询按预期工作，我认为这应该可以解决问题：

SELECT sum1.tot + sum2.tot 
FROM  
(SELECT SUM(opn3.samt) as tot
FROM PUB.ord ord3, PUB.opn opn3
WHERE
ord3.subsnum = opn3.subsnum
AND ord3.onum = opn3.onum
AND ord3.DM1 != ''
AND ord3.DM1 IN('XCWAJC25','WCWAMO73') 
AND ord3.prdcde = 'CSC' 
AND ord3.stat != 16
AND opn3.samt >= 0
GROUP BY ord3.DM1, ord3.prdcde) sum1,

(SELECT SUM((-1 * opn2.samt) + ord2.samt) as tot
FROM PUB.ord ord2, PUB.opn opn2
WHERE
ord2.subsnum = opn2.subsnum
AND ord2.onum = opn2.onum
AND ord2.DM1 != ''
AND ord2.DM1 IN('XCWAJC25','WCWAMO73') 
AND ord2.prdcde = 'CSC' 
AND ord2.stat = 16
AND opn2.samt < 0
GROUP BY ord2.DM1, ord2.prdcde) sum2

【讨论】：