기본

컬럼 추가

ALTER TABLE tbl_name ADD COLUMN new_col_name COLUMN_TYPE;

ALTER TABLE tbl_name ADD COLUMN new_col_name COLUMN_TYPE DEFAULT 'ABC';

ALTER TABLE tbl_name ADD COLUMN new_col_name COLUMN_TYPE DEFAULT 'ABC' NOT NULL;

컬럼 제거

ALTER TABLE tbl_name DROP col_name;

이름 변경

ALTER TABLE tbl_name RENAME COLUMN col_name TO new_name;

코멘트 설정

COMMENT ON COLUMN tbl_name.col_name IS '컬럼 코멘트';

코멘트 제거

COMMENT ON COLUMN tbl_name.col_name IS NULL;

타입

타입 변경

ALTER TABLE tbl_name ALTER COLUMN col_name TYPE COLUMN_TYPE;

타입 변경 + 일괄 값 변경

ALTER TABLE tbl_name ALTER COLUMN col_name TYPE COLUMN_TYPE USING col_name::COLUMN_TYPE;

제약

NOT NULL 제약 추가