在 Oracle 中用 Case Select 计数

Question

我有以下查询：

SELECT t.range,
       Count(*)
FROM (
    SELECT CASE 
            WHEN creditscore BETWEEN 300
                    AND 499
                THEN '[300, 499]'
            WHEN creditscore BETWEEN 500
                    AND 699
                THEN '[500, 699]'
            WHEN creditscore BETWEEN 700
                    AND 850
                THEN '[700, 850]'
            END AS range
    FROM customer
    ) T
GROUP BY t.range;

这给了我以下内容：

CS range     COUNT(*)
---------- ----------
[700, 850]          7
[500, 699]         13

我想要以下输出：

CS range     COUNT(*)
---------- ----------
[300, 499]          0
[500, 699]         13
[700, 850]          7

谁能帮帮我？

更新

我执行了 Justin 提供的代码。它给了我以下内容：

DESCRIPTIO   COUNT(*)
---------- ----------
[300, 499]          1
[700, 850]          7
[500, 699]         13

SQL> SELECT COUNT(*) FROM customer where creditscore BETWEEN 300 AND 499;

COUNT(*)
----------
         0

Answer 1

一个选择是做类似

的事情

WITH ranges AS (
  SELECT '[300, 499]' description, 300 min_val, 499 max_val FROM dual
  UNION ALL
  SELECT '[500, 699]' description, 500 min_val, 699 max_val FROM dual
  UNION ALL
  SELECT '[700, 850]' description, 700 min_val, 850 max_val FROM dual
)
SELECT r.description, count(creditscore)
  FROM ranges r
       LEFT OUTER JOIN customer c 
         ON (c.creditscore BETWEEN r.min_val AND r.max_val)
 GROUP BY r.description

通常，您希望为您的范围设置一个永久的 table 以防将来有人想要添加或修改它们。但是您可以像我在这里那样对查询中的范围进行硬编码。

Answer 2

在这种情况下，您可以使用 unpivot。你的回答-

Select * From
(
Select Sum(Col1) "[300, 499]", Sum(Col2) "[500, 699]", Sum(Col3) "[700, 850]"
From (
    Select Case 
            When Creditscore Between 300
                    And 499
                Then 1 Else 0 End As Col1,
            Case When Creditscore Between 500
                    And 699
                Then 1  Else 0 End Col2,
            Case When Creditscore Between 700
                    And 850
                Then 1  Else 0 End Col3
    From Customer
    )
)
Unpivot
(
  "Count"
  For
  "Description" In ("[300, 499]", "[500, 699]", "[700, 850]")
);

结果-

Description  Count
[300, 499]    0
[500, 699]    4
[700, 850]    3

在 Oracle 中用 Case Select 计数

Count with Case Select in Oracle

oracle

select

case