SQL查詢來比較3個表，並得到回答

Question

幫我請了一些SQL查詢..

我有3個表：

CREATE TABLE cars (
    id integer not null primary key, -- id of car 
    name text not null, -- car name 
) 

- 事故

CREATE TABLE accidents (
    id integer not null primary key, -- id of accident 
    place text not null, -- place of accident 
    a_date date not null -- date of accident 
) 

- 結果事故

CREATE TABLE outcomes (
    car_id integer not null, -- id of car 
    accident_id integer not null, -- id of accident 
    result smallint not null, -- result: 0 - fine, 1 - scratched, 2 - crashed 
    CONSTRAINT outcomes_pkey PRIMARY KEY (car_id, accident_id) 
) 

我需要一個sql查詢得到曾經被劃傷的汽車，並且再次發生事故，當然墜毀的汽車不會出現其他事故。

Answer 1

試試這個

select c.id, c.name, count(distinct o.results) cnt 
from cars c 
inner join outcomes o on c.id = o.car_id 
where o.results in (1,2) 
group by c.id, c.name 
having count(distinct o.results) > 1;