Benefiting from the Relational System - Mastering phpMyAdmin 3.4 for Effective MySQL Management - page 179

Benefiting from the
Relational System
The relational system allows users to work more closely with phpMyAdmin,
as we will see in the following chapters. This chapter explains how to define
inter-table relations.
Relational MySQL
When application developers use PHP and MySQL to build web interfaces or other
data manipulation applications, they usually establish relations between tables using
the underlying SQL queries. Examples of this would be queries to "get an invoice
and all its items" and "get all topics by an author".
In the earlier versions of phpMyAdmin, the relational data structure (how tables
relate to each other) was not stored within MySQL. Tables were programmatically
joined by the applications to generate meaningful results.
This was considered a shortcoming of MySQL by phpMyAdmin developers and
users. Therefore, the team started to build an infrastructure to support relations for
MyISAM tables, which is now called the phpMyAdmin configuration storage. The
infrastructure evolved to support a growing array of special features such as query
bookmarks and MIME-based transformations.
Now-a-days, relations between tables are normally defined natively with the
FOREIGN KEY feature of the InnoDB and PBXT storage engines. phpMyAdmin
supports both this type of relations and those defined for MyISAM .