Open devLupin opened 6 months ago
SELECT <COLUMN LIST> FROM TABLE1 AS T1
<JOIN TYPE> TABLE2 AS T2
ON <조건>
INNER JOIN == JOIN
FULL OUTER JOIN(전체 집합)
LEFT JOIN
과 RIGHT JOIN
을 UNION
UNION
은 DISTINCT 포함이라 자동 중복제거UNION ALL
SELECT DISTINCT
JOIN
전에 중복 제거
LEFT JOIN ( SELECT DISTINCT COL1, COL2 FROM TABLE1) AS A