SQL フィドル
Oracle 11g R2 スキーマのセットアップ:
CREATE TABLE car
(vin varchar2(9), customer_id varchar2(8), model_id varchar2(6))
;
INSERT ALL
INTO car (vin, customer_id, model_id)
VALUES ('222313XYZ', 'cust1234', 'toyota')
INTO car (vin, customer_id, model_id)
VALUES ('123232SSS', 'cust1234', 'toyota')
INTO car (vin, customer_id, model_id)
VALUES ('111111ERE', 'cust1111', 'bmw')
INTO car (vin, customer_id, model_id)
VALUES ('999999LKO', 'cust1234', 'bmw')
SELECT * FROM dual
;
クエリ 1 :所有者が複数のトヨタを所有しているすべてのモデルを表示する場合
select vin, customer_id, model_id from (
select vin, customer_id, model_id,
count( decode(model_id, 'toyota', 1) ) over (partition by customer_id) cnt
from car
)
where cnt > 1
結果:
| VIN | CUSTOMER_ID | MODEL_ID |
--------------------------------------
| 999999LKO | cust1234 | bmw |
| 222313XYZ | cust1234 | toyota |
| 123232SSS | cust1234 | toyota |
クエリ 2 : 所有者が複数のトヨタを所有しているトヨタのみを表示する場合:
select vin, customer_id, model_id from (
select vin, customer_id, model_id,
count(*) over (partition by customer_id) cnt
from car
where model_id = 'toyota'
)
where cnt > 1
結果:
| VIN | CUSTOMER_ID | MODEL_ID |
--------------------------------------
| 123232SSS | cust1234 | toyota |
| 222313XYZ | cust1234 | toyota |