How to link an intermediary table
(This was done with MySQL, Hibernate and Lombok)
Setting: We have two Entities, Category and Code. Some categories must contain x codes, others cannot contain y codes and we want to leave open the possibility to “must contain z but not p” at the same time.
How: At database level we’ll have 4 tables with the following structure
client_category
| FIELD_NAME | FIELD_TYPE | CONSTRAINTS |
|---|---|---|
| id | bigint(19) | PK (primary key) |
| example_string | varchar(255) | |
| example_bool | tinyint(1) |