관계대수

[Quiz1]

• - 1. R ∩ S

/* mySQL은 실행 안됨

SELECT name, dept, gender FROM R

INTERSECT

SELECT name, dept, gender FROM S; */

• - 2. R ∪ S

SELECT name, dept, gender FROM R

UNION

SELECT name, dept, gender FROM S;

• - 3. R - S

/* mySQL은 실행 안됨, MINUS(Oracle)

SELECT name, dept, gender FROM R

MINUS

SELECT name, dept, gender FROM S; */