mysql - 来自同一表的多个求和查询和多个 where 条件

Question

我有 2 个查询要放入其中一个，然后按 fName 分组。我尝试了数百次，但无法正常工作。

 SELECT fName, code, 
 SUM(totalOr) AS totOr
 FROM person
 WHERE code = '4'
 GROUP BY fName

 SELECT fName, code, 
 SUM(totalPl) AS totPl
 FROM person
 WHERE code = '1'
 GROUP BY fName

Answer 1

你可以使用CASE语句

SELECT 
    fName,
    code,
    SUM(CASE WHEN code = 1 THEN totalOr ELSE 0 END) AS totOr,
    SUM(CASE WHEN code = 4 THEN totalPl ELSE 0 END) AS totP1
FROM
    person
WHERE
    code IN ('1' , '4')
GROUP BY fName, code;