sql - 联合所有和总和

Question

我有 2 个表:

表 1

mmsi   type   l   w   flag   value
123    456    A   B   C      37
236    567    X   Y   Z      28

表2

mmsi   type   l   w   flag   value
123    456    A   B   C      30
234    567    X   Y   Z      20

我想运行一个查询来获取唯一值，并为每一行获取存储在最后一个字段中的值的总和:

决赛 table

mmsi   type   l   w   flag   value
123    456    A   B   C      67
234    567    X   Y   Z      20
236    567    X   Y   Z      28

我该怎么做？我正在尝试使用 UNION ALL 和 SUM

SELECT "mmsi", "type", "l", "w", "flag", "value", SUM ("value")
FROM (SELECT "mmsi", "type", "l", "w", "flag", "value" FROM "table 1" UNION ALL
SELECT "mmsi", "type", "l", "w", "flag", "value" FROM "table 2") as def
GROUP BY "mmsi", "type", "l", "w", "flag", "value"

但这给了我以下错误的结果:

mmsi   type   l   w   flag   value  sum
123    456    A   B   C      37     37
123    456    A   B   C      30     30
234    567    X   Y   Z      20     20
236    567    X   Y   Z      28     28

谢谢!

Answer 1

您需要从 select 和 group by 中删除 value:

SELECT "mmsi", "type", "l", "w", "flag", SUM("value")
FROM (SELECT "mmsi", "type", "l", "w", "flag", "value" FROM "table 1" 
      UNION ALL
      SELECT "mmsi", "type", "l", "w", "flag", "value" FROM "table 2"
     ) as def
GROUP BY "mmsi", "type", "l", "w", "flag";