Alter to add primary key
SQL> SQL> CREATE TABLE supplier 2 ( supplier_id numeric(10) not null, 3 supplier_name varchar2(50) not null, 4 contact_name varchar2(50) 5 ); Table created. SQL> SQL> desc supplier; Name Null? Type ----------------------------------------------------------------------------------------------------- -------- -------------------------------------------------------------------- SUPPLIER_ID NOT NULL NUMBER(10) SUPPLIER_NAME NOT NULL VARCHAR2(50) CONTACT_NAME VARCHAR2(50) SQL> SQL> ALTER TABLE supplier 2 add CONSTRAINT supplier_pk PRIMARY KEY (supplier_id); Table altered. SQL> SQL> desc supplier; Name Null? Type ----------------------------------------------------------------------------------------------------- -------- -------------------------------------------------------------------- SUPPLIER_ID NOT NULL NUMBER(10) SUPPLIER_NAME NOT NULL VARCHAR2(50) CONTACT_NAME VARCHAR2(50) SQL> SQL> drop table supplier; Table dropped. SQL> SQL>