Question

我有三个表镇，病人家，患者记录

城镇

标识
  1
  2
  3

患者家

Id | SERIAL_NUMBER
  1 | 11
  2 | 12个
  2 | 13

患者记录

状态| SERIAL_NUMBER
  稳定| 11
  到期| 12
  到期| 13

我希望根据患者记录对来自城镇的每个Id进行稳定计数和过期患者。

输出应该像

结果

ID | stableRecords | expiredRecords
  1 | 1 | 0
  2 | 0 | 2
  3 | 0 | 0

Answer 1

假设patientsHome.ID实际上是towns.ID的外键，您可以加入3个表，根据需要进行过滤，按城镇分组，并计算行数：

SELECT t.Id, COUNT(*) as patientCount
FROM towns t
  INNER JOIN patientsHome ph
    on t.Id = ph.Id
  INNER JOIN patientsRecords pr
    on ph.serialNumber = pr.serialNumber
WHERE pr.status in ('stable', 'expire')
GROUP BY t.Id;

如果您还想对每个城镇的状态进行分类：

SELECT t.Id, pr.status, COUNT(*) as patientCount
... FROM, WHERE same as above
GROUP BY t.Id, pr.status;

Answer 2

试试这个：

SELECT t.id, pr.status,
  COUNT(*) AS countByStatus
FROM patientsRecords pr
INNER JOIN patientsHome ph
ON ph.serial_number = pr.serial_number
INNER JOIN towns t
ON t.id=ph.id
WHERE pr.status  IN ('stable', 'expire')
GROUP BY t.id, pr.status;

请参阅sqlfiddle：http://sqlfiddle.com/#!2/028545/4

Answer 3

试试这样：

select t.id,case when tt.StableRecords is null then 0 else tt.StableRecords end
as StableRecords,case when tt.expiredRecords is null then 0 else tt.expiredRecords
end as expiredRecords from towns t left join
(select ph.id, count(case when pr.status='stable' then 1 end) as StableRecords,
count(Case when pr.status='expire' then 1 end) as expiredRecords
from patientsRecords pr inner join 
patientsHome ph on ph.serial_number=pr.serial_number
group by ph.id ) as tt 
on t.id=tt.id

链接三个表SQL

3 个答案: