Question

Lets assume I have the following table

create table Article
(
  ART_ID        bigint not null auto_increment,
  ART_NAME      varchar(25) not null,
  ART_COST      decimal(8,2) not null,
  ART_DESC      text,
  primary key(ART_ID)
);

and also this table

create table Fruits
(
  FRUITS_ID     bigint not null auto_increment,
  FRUITS_TYPE   varchar(15),
  FRUITS_FROZEN timestamp DEFAULT CURRENT_TIMESTAMP,
  primary key(FRUITS_ID )
);

I want the Fruits table to have all the fields of the table Article. How can I implement this? Should I reference it by some relation or is there another trick?

Answer 1

I think what you need here is to add an ARTICLE_ID field to Fruits, and then reference it to Articles.ART_ID via a FOREIGN KEY constraint to ensure data consistency.

Note that this means that for each fruit, to have some “article” fields set, a corresponding record in Articles must exist. If you don’t want article fields to be mandatory for a fruit, you can make the ARTICLE_ID field nullable. This still allows a foreign key to be defined, but it will only enforce a reference if the value stored in ARTICLE_ID is not NULL.