SQL> -- drop a 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> ALTER TABLE supplier
2 drop CONSTRAINT supplier_pk;
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>
SQL>
SQL>
