Oracle

Defining Constraints

Figo Kim 2006. 11. 23. 21:16

  • Column-level constraint:

    
CREATE TABLE employees(
    
   employee_id   NUMBER(6)
    
      CONSTRAINT emp_emp_id_pk PRIMARY KEY,
    
   first_name    VARCHAR2(20),
    
   ...);



  • Table-level constraint:

    
CREATE TABLE employees(
    
  employee_id   NUMBER(6),
    
  first_name    VARCHAR2(20),
    
  ...
    
  job_id        VARCHAR2(10) NOT NULL,
    
  CONSTRAINT    emp_emp_id_pk
    
    PRIMARY_KEY(EMPLOYEE_ID));