SQL：集团在个别结果行计数(SQL: Group counts in individual res

2019-09-29 03:34发布

当我运行查询号码1：

SELECT id, name, COUNT(name) AS count 
  FROM markers 
 WHERE state like 'OR' 
group by named

我得到如下结果：

id  name                count
14  Alsea               2
76  Applegate Valley    1
3   Ashland             9
64  Beaver              1
26  Bend                1
10  Carlton             2

这是很好，除了，我要计数的名称的每个实例，其各自的ID显示为在查询号2的结果可以看出：

SELECT id, name, COUNT(name) AS count 
  FROM markers 
WHERE state like 'OR' 
group by name, id

这将产生以下结果：

id  name                count
14  Alsea               1
28  Alsea               1
76  Applegate Valley    1
3   Ashland             1
13  Ashland             1
16  Ashland             1
20  Ashland             1
22  Ashland             1
43  Ashland             1
48  Ashland             1
51  Ashland             1
72  Ashland             1
64  Beaver              1
26  Bend                1
10  Carlton             1
27  Carlton             1

是否有一个查询我可以运行，将返回从查询号码2 ID和名称，并从查询号码1对应的计数每行中，如下图所示？

id  name                count
14  Alsea               2
28  Alsea               2
76  Applegate Valley    1
3   Ashland             9
13  Ashland             9
16  Ashland             9
20  Ashland             9
22  Ashland             9
43  Ashland             9
48  Ashland             9
51  Ashland             9
72  Ashland             9
64  Beaver              1
26  Bend                1
10  Carlton             2
27  Carlton             2

Answer 1:

尝试这个：

SELECT id, name, 
 (SELECT COUNT(name) 
   FROM markers im 
   WHERE state like 'OR' 
   GROUP BY name 
   HAVING im.name=m.name) as count
FROM markers m 
WHERE state like 'OR' 
GROUP BY name, id

Answer 2:

您可以使用：

   SELECT t.id,
          t.name,
          COALESCE(x.cnt, 0) AS count
     FROM MARKERS t
LEFT JOIN (SELECT m.name,
                  COUNT(m.*) AS cnt
             FROM MARKERS m
            WHERE m.state LIKE 'OR'
         GROUP BY n.name) x ON x.name = t.name
     WHERE t.state LIKE 'OR'
  GROUP BY t.id, t.name