[mysql] PRIMARY KEY, UNIQUE KEY

PRIMARY KEY(기본키)

테이블 생성 시

CREATE TABLE table_name (
	col1 int(11) PRIMARY KEY
)

CREATE TABLE table_name (
	col1 int(11),
	col2 int(11),
	PRIMARY KEY (col1, col2)
)

추가

ALTER TABLE table_name ADD PRIMARY KEY (col1)

삭제

ALTER TABLE table_name DROP PRIMARY KEY

UNIQUE KEY(유니크키)

테이블 생성 시

CREATE TABLE table_name (
	col1 int(11),
	col2 int(11),
	UNIQUE KEY unique_name (col1, col2)
)

추가

ALTER TABLE table_name ADD UNIQUE KEY unique_name (col1, col2)

삭제

ALTER TABLE table_name DROP INDEX unique_name