Oracle SQL 总和

Question

询问

SELECT
SUM(CASE A WHEN A = B THEN 1 ELSE 0 END) AS CASE A,
SUM(CASE B WHEN B = C THEN 1 ELSE 0 END) AS CASE B,
SUM(CASE C WHEN C = D THEN 1 ELSE 0 END) AS CASE C
FROM TABLE SAMPLE_1 S_1 LEFT JOIN SAMPLE_2 S_2 ON (S_1.ID = S_2.ID)
WHERE NUMBER = '12345'

如何在最后制作一列，返回所有条件总和的总和。 任何和所有的帮助表示赞赏。

Answer 1

首先，您的代码不是有效的 SQL。 也许你的意思是：

SELECT
    SUM(CASE WHEN A = B THEN 1 ELSE 0 END) AS CASE_A,
    SUM(CASE WHEN B = C THEN 1 ELSE 0 END) AS CASE_B,
    SUM(CASE WHEN C = D THEN 1 ELSE 0 END) AS CASE_C
FROM TABLE SAMPLE_1 S_1 
LEFT JOIN SAMPLE_2 S_2 ON S_1.ID = S_2.ID
WHERE NUMBER = '12345'

这基本上假设A 、 B和C是来自查询中涉及的两个表之一的列。 我强烈建议使用表别名来限定它们以使其明确。 也不是NUMBER是 Oracle 中的保留字 - 希望这不是您的实际列名，否则需要用双引号括起来。

现在，如果您想要将三个条件相加的另一列，则可能是：

SELECT
    SUM(CASE WHEN A = B THEN 1 ELSE 0 END) AS CASE_A,
    SUM(CASE WHEN B = C THEN 1 ELSE 0 END) AS CASE_B,
    SUM(CASE WHEN C = D THEN 1 ELSE 0 END) AS CASE_C,
    SUM(CASE WHEN A = B OR B = C OR C = D THEN 1 ELSE 0 END) AS CASE_ABC
FROM TABLE SAMPLE_1 S_1 
LEFT JOIN SAMPLE_2 S_2 ON S_1.ID = S_2.ID
WHERE NUMBER = '12345'

这是三个条件的交集，不一定与每个条件中匹配项的总和相同。 如果是这样，要么重复表达式，要么使用子查询：

SELECT t.*, CASE_A + CASE_B + CASE_C AS CASE_ABC
FROM (
    SELECT
        SUM(CASE WHEN A = B THEN 1 ELSE 0 END) AS CASE_A,
        SUM(CASE WHEN B = C THEN 1 ELSE 0 END) AS CASE_B,
        SUM(CASE WHEN C = D THEN 1 ELSE 0 END) AS CASE_C
    FROM TABLE SAMPLE_1 S_1 
    LEFT JOIN SAMPLE_2 S_2 ON S_1.ID = S_2.ID
    WHERE NUMBER = '12345'
) t

Answer 2

您可以简单地在查询中添加+如下（ CASE语句也已更正）：

SELECT
SUM(CASE WHEN A = B THEN 1 ELSE 0 END) 
+ SUM(CASE WHEN B = C THEN 1 ELSE 0 END) 
+ SUM(CASE WHEN C = D THEN 1 ELSE 0 END) AS sum_of_all_condition
FROM TABLE SAMPLE_1 S_1 LEFT JOIN SAMPLE_2 S_2 ON (S_1.ID = S_2.ID)
WHERE NUMBER = '12345'