查询计数 Else 语句值时的 SQL 案例答案

【问题标题】：SQL Case When Query Count Else Statement Values查询计数 Else 语句值时的 SQL 案例
【发布时间】：2019-08-07 01:45:13
【问题描述】：

在我的查询中，我有多个 Case When 子句，其中一个表中的唯一数字字符串将指示输出中的唯一字符串/句子值。我目前的问题是我的 Case When 输出正在处理输出中的总计数，但是由于存在多个唯一字符串，这些字符串不在第一个表中，而在第二个表中存在，应该在 else 语句中总计为一个总数，每个计数都在自己的行中。

我尝试在查询结束时对 GROUP BY 子句执行 ROLLUP，但没有得到我想要的预期输出。

这是我现在正在使用的：

SELECT 
  F.Identifier, F.Videogame, F.Developer,
CASE WHEN S.String='1581' THEN 'Made by billy'
     WHEN S.String='1903' THEN 'Made by bob'
     WHEN S.String='5849' THEN 'Made by lilly'
     ELSE 'worked on by someone else' END AS Final_Name,
     COUNT(distinct S.User_ID) as Count
FROM 
  table1 as F
JOIN 
  table2 as S
ON
  F.Identifier=S.Identifier
GROUP BY
  F.Identifier, F.Videogame, F.Developer, S.String

这是我目前得到的输出：

abcd | red dead | company1 | worked on by someone else | 1
abcd | red dead | company1 | Made by billy             | 1
defg | halo 3   | company2 | Made by bob               | 1
defg | halo 3   | company2 | worked on by someone else | 1
defg | halo 3   | company2 | worked on by someone else | 1
hijk | fortnite | company3 | Made by lilly             | 1

这是我想要实现的输出：

abcd | red dead | company1 | worked on by someone else | 1
abcd | red dead | company1 | Made by billy             | 1
defg | halo 3   | company2 | Made by bob               | 1
defg | halo 3   | company2 | worked on by someone else | 2
hijk | fortnite | company3 | Made by lilly             | 1

【问题讨论】：

标签： sql google-bigquery

【解决方案1】：

以下是 BigQuery 标准 SQL

#standardSQL
SELECT F.Identifier, F.Videogame, F.Developer,
CASE WHEN S.String='1581' THEN 'Made by billy'
     WHEN S.String='1903' THEN 'Made by bob'
     WHEN S.String='5849' THEN 'Made by lilly'
     ELSE 'worked on by someone else' END AS Final_Name,
     COUNT(DISTINCT S.User_ID) AS COUNT
FROM `project.dataset.table1` AS F
JOIN `project.dataset.table2` AS S
ON F.Identifier=S.Identifier
GROUP BY F.Identifier, F.Videogame, F.Developer, Final_Name

如您所见，唯一的解决方法是在最后一行 - 您需要使用 S.String 而不是 Final_Name

因此，如果将上述应用于您问题中的采样数据 - 结果是

Row Identifier  Videogame   Developer   Final_Name                  Count    
1   abcd        red dead    company1    worked on by someone else   1    
2   abcd        red dead    company1    Made by billy               1    
3   defg        halo 3      company2    Made by bob                 1    
4   defg        halo 3      company2    worked on by someone else   2    
5   hijk        fortnite    company3    Made by lilly               1

【讨论】：

非常感谢您的帮助！我想知道您是否也可以看看我刚刚发布的问题。我真的很感激！
当然。很快就会检查它。同时考虑投票给答案，如果还没有:o)

【解决方案2】：

这就是你需要的。

SELECT 
  F.Identifier, F.Videogame, F.Developer,
CASE WHEN F.String='1581' THEN 'Made by billy'
     WHEN F.String='1903' THEN 'Made by bob'
     WHEN F.String='5849' THEN 'Made by lilly'
     ELSE 'worked on by someone else' END AS Final_Name,
     S.cnt as Count
FROM 
  table1 as F
JOIN 
  (select a.Identifier, b.Developer, count(1) cnt from table2  a
     join table1 b on b.Identifier = a.Identifier
    Group by String, b.Developer) as S
    ON
      F.Identifier=S.Identifier and S.Developer = F.Developer

【讨论】：