with table1 as (

select course_id, count(distinct(user_id)) as cnt_checkins from checkins

group by course_id

), table2 as (

select course_id, count(*) as cnt_total from orders

group by course_id

)

select c.title,

    a.cnt_checkins,

    b.cnt_total,

    (a.cnt_checkins/b.cnt_total) as ratio

from table1 a inner join table2 b on a.course_id = b.course_id

inner join courses c on a.course_id = c.course_id

위에 코드는 동영상에선 오류가 나지 않은 정답코드입니다. 하지만 제꺼에선 syntax 에러가 나더라구요

그래서 밑의 문장으로 해결했습니다.

with table1 as (

select course_id, COUNT(DISTINCT(user_id)) as cnt_checkins from checkins c 

group by course_id

), table2 as (

select course_id, COUNT(*) as cnt_total from orders

group by course_id

)

select c2.title ,

 a.course_id, 

 a.cnt_checkins, 

 b.cnt_total, 

 (a.cnt_checkins / b.cnt_total) as radio 

from  table1 a

inner join table2 b on a.course_id = b.course_id

inner join courses c2 on a.course_id = c2.course_id 

with 절과 select 문을 붙여주었더니 정상 작동합니다.

SQL 도 파이썬의 들여쓰기와 같이 줄바꿈이 큰 영향을 끼치는지 궁금합니다.