Oracle 11g: Creating Constraints

Types Of Constraints

• not null
• primary key
• foreign key
• check
• unique

===>  SQL Queries: Column Level

create table employee_column_level
(
  employee_id number(6) CONSTRAINT emp_emp_level_id_pk primary key,
  first_name varchar2(20)
);







create table employee_table_level
(
  employee_id number(6),
  first_name varchar2(20),
  CONSTRAINT emp_emp_table_id_pk primary key (employee_id)
);