INNER JOIN #
sql
SELECT
l.Title,
r.Name
FROM
albums AS l
INNER JOIN
artists AS r
ON
r.ArtistId = l.ArtistId;
sql
SELECT
Title,
Name
FROM
albums
INNER JOIN artists USING(ArtistId);LEFT JOIN #
sql
SELECT
Name,
Title
FROM
artists
LEFT JOIN albums ON artists.ArtistId = albums.ArtistId
ORDER BY
Name;SELF JOIN #
sql
SELECT m.firstname || ' ' || m.lastname AS 'Manager',
e.firstname || ' ' || e.lastname AS 'Receives reports from'
FROM
employees e
INNER JOIN
employees m
ON
m.employeeid = e.reportsto
ORDER BY
manager;- ‘A 테이블’과 A 테이블의 복사본인 ‘B 테이블’을 합치기
Grouping Data #










