CODE EXAMPLE FOR SQL

SQL TABLE : SUBSCRIPTION, PRODUCT, SPECIFICATION

create table SUBSCRIPTION (
  MSISDN int(13),
  PRODUCT_ID int(7),
  EFFECTIVE_DATE date&time,
  EXPIRED_DATE date&time,
  PRIMARY KEY (PRODUCT_ID));

create table PRODUCT (
  PRODUCT_ID int(7),
  PRODUCT_NAME varchar(30),
  FOREIGN KEY (PRODUCT_ID));
  
create table SPECIFICATION (
  PRODUCT_ID int(7),
  PRICE int(8),
  FOREIGN KEY (PRODUCT_ID));