Mega Code Archive

 

Categories / Oracle PLSQL / Constraints

 

Enable 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  disable 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> ALTER TABLE supplier   2  enable 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>