PostgresSQL/MySQLとの違い

LIMIT †

[MySQL  ] LIMIT start, count
[Postgres] LIMIT count  OFFSET start

[MySQL   ] SELECT * FROM table LIMIT 0,3;
[Postgres] SELECT * FROM table LIMIT 3 OFFSET 0;

GROUP BY †

[MySQL   ] SELECT * FROM table GROUP BY code;   ←PostgresではNG
[Postgres] SELECT code FROM table GROUP BY code;

DISTINCT †

[MySQL   ] SELECT DISTINCT code FROM table;
[Postgres] SELECT DISTINCT code FROM table;
[Postgres] SELECT DISTINCT ON(code) * FROM table;