Question

我有一张像

这样的表格

name_id     disease_id   
-------     ----------    
1           1    
1           2    
2           2    
3           1    
3           3    
4           1    
4           2    
5           2

我需要在整个表格中找到疾病的独特组合。我不能按name_id进行分组，因为这会产生非不同的组合（请参阅name_id 1和4）。我不能省略GROUP BY，它会在所有name_id中生成一个简单的disease_id列表。

我希望能够回答的问题是：人群中发生的儿童疾病的独特组合是什么（以后可能会增加计数：

Chickenpox          (10)
Chickenpox+Measles  (2)
Measles             (5)
Measles+Mumps       (1)
etc.

Answer 1

你希望能够回答像＃34这样的问题：人群中发生的儿童疾病的独特组合是什么？＃34;

我的回答基于以下假设：

disease_id指水痘，麻疹，腮腺炎等
name_id指病人
disease_id 1指＆＃39;水痘＆＃39;和疾病_id 3指麻疹＆＃39 ;;两者都被认为是儿童疾病。（这只是例如，你的可以不同）

基于以上假设，下面的查询会产生所需的结果：

SELECT 'Chickenpox' as 'DiseaseName', COUNT(*) as 'Patients' 
FROM (
    SELECT name_id FROM table GROUP BY name_id HAVING COUNT(*) = 1 WHERE disease_id  = 1
    ) d1
UNION 
SELECT 'Measles' as 'DiseaseName', COUNT(*) as 'Patients' 
FROM (
    SELECT name_id FROM table GROUP BY name_id HAVING COUNT(*) = 1 WHERE disease_id = 3
    ) d3
UNION
SELECT 'Chickenpox + Measles' as 'DiseaseName', COUNT(*) as 'Patients' 
FROM (
    SELECT name_id FROM table GROUP BY name_id HAVING COUNT(*) = 2 WHERE disease_id IN (1,3) 
    ) d1d3

结果将如下：

DiseaseName           Patients
--------------------  ---------
Chickenpox            10
Measles               5
Chickenpox+Measels    2

Answer 2

解决方案有两个步骤。

列举每位患者患有的疾病;将其存储在一个单独的表中
使用上表列出疾病的不同组合以及患有这些组合的患者数量。

现在，对于步骤＃1，您需要一个存储过程，如下所示：

DECLARE @prv int
DECLARE @nid int
DECLARE @dname varchar(100)
DECLARE @combi varchar(500)

DECLARE c1 CURSOR FOR
SELECT name_id, disease_name 
FROM patients 
JOIN diseases ON patients.disease_id = diseases.disease_id
ORDER BY name_id, disease_name;

DELETE FROM diseasecombi;

OPEN c1
FETCH NEXT FROM c1 INTO @nid, @dname 
SET @prv = @nid
SET @combi = ''

WHILE @@FETCH_STATUS = 0
BEGIN
    IF @prv <> @nid
    BEGIN
        INSERT INTO diseasecombi (name_id, suffers) VALUES (@prv, @combi)
        SET @prv = @nid
        SET @combi = ''
    END
    IF LEN(@combi) > 0 SET @combi = @combi + ', '
    SET @combi = @combi + @dname
    FETCH NEXT FROM c1 INTO @nid, @dname
END
INSERT INTO diseasecombi(name_id, suffers) VALUES (@prv, @combi)

CLOSE c1
DEALLOCATE c1

上面的存储过程将生成一个看起来像

name_id suffers
------- -------------------------------
1       Chickenpox, Mumps
2       Chickenpox, Fibroids, Measles
3       Chickenpox, Mumps
4       Chickenpox, Measles
5       Chickenpox, Measles
6       Chickenpox
7       Rashes

对于步骤＃2，查询如下：

SELECT suffers, COUNT(*) AS Patients 
FROM diseasecombi
GROUP BY suffers
ORDER BY suffers

产生输出如下：

Diseases                        Patients
------------------------------  ----------
Chickenpox                      1
Chickenpox, Fibroids, Measles   1
Chickenpox, Measles             2
Chickenpox, Mumps               2
Rashes                          1

如何获得不同的群组

2 个答案: