Valentina Example: Usage of ObjPtr and Binary Links
The “valentina_links” sample database was developed to demonstrate the usage of the special relation kinds, that are available only in Valentina:
This database contains three tables describing the sales in the abstract bookstore:
- tblBooks – contains the list of books in the store;
- tblCustomers – contains info about customers of the store;
- tblOrders – constains info about purchases.
The relations between entities in the database described in the table below:
|tblBooks||M : M||tblOrders|
|tblCustomers||1 : M||tblOrders|
Using any other relational database to implement these relations, you should use primary and foreign keys, and moreover, additional table to implement the M:M relation. You should not do this with Valentina. The Valentina engine provides special kinds of links to implement relations between database entities:
- Binary Link – to implement any kind of relations, including M:M.
The schema, that uses these links is shown in the picture below.
Using this database you can:
- explore the technique of usage ObjPtr ang Binary Links;
- familiarize with presentation data in the related data editor;
- feel the power and advantages of Valentina engine.