Use combined column as the primary key : Primary Key « Table « Oracle PL/SQL Tutorial

SQL>
SQL> create table myTable(
  2  id               number(6) not null,
  3  salary           number(8,2),
  4  hire_date        date default sysdate,
  5  termination_date date,
  6  termination_desc varchar2(4000),
  7  constraint       emphistory_pk primary key (id, hire_date)
  8  );

Table created.

SQL>
SQL> describe myTable;
 Name                  Null?    Type
--------------------------------------------------------------------------
 ID                    NOT NULL NUMBER(6)
 SALARY                         NUMBER(8,2)
 HIRE_DATE             NOT NULL DATE
 TERMINATION_DATE               DATE
 TERMINATION_DESC               VARCHAR2(4000)

SQL>
SQL>
SQL> drop table myTable;

Table dropped.

6.15.Primary Key
	6.15.1.	Create a table with primary key, VARCHAR type column and date type column with default value
	6.15.2.	Alter table to insert primary key
	6.15.3.	Use combined column as the primary key
	6.15.4.	Try to add two primary keys to one table
	6.15.5.	All columns as primary key
	6.15.6.	One to many using a primary-key and foreign-key relationship
	6.15.7.	One-to-one using a primary-key and foreign-key relationship
	6.15.8.	Use three columns as primary key