SQL 예제로 구조 파악하기

create table EMPLOYEE ( 
   id                  INT                 PRIMARY KEY,
   name                VARCHAR(20)         NOT NULL,
   birth_date          DATE,
   sex                 CHAR(1)             CHECK(sex in ('M', 'F')),
   position            VARCHAR(10),
   salary              INT                 DEFAULT 50000000,
   dept_id             INT,
   FOREIGN KEY (dept_id) references DEPARTMENT(id) 
       on delete SET NULL on update CASCADE,
   CHECK (salary >= 50000000)
   );