CHAPTER 14: Android Content Providers: Providing Data to Applications 507Database Fundamentals: Concepts and Terms
A database management system, or DBMS, is a data storage system or engine that can store
valuable data that can be easily accessed, read, and updated. This capability is quite desirable for a
software development platform like Android.
If you have never been exposed to database technology, this section covers database fundamentals.
Popular database software packages that you may be familiar with include Microsoft Access and
Claris FileMaker Pro. The company that currently develops FileMaker is known as FileMaker, Inc.
As you know, there is a complete open source DBMS inside of the Android OS called SQLite, which
is actually something called a Relational DBMS, or RDBMS. An RDBMS is based on relationships
that can be drawn between data that is arranged using tables. These data tables support rows
of data and columns of data. This is similar to a spreadsheet program like Excel, except that data
in a relational database is not usually visible at the same time, like data in a spreadsheet is. It is
important to note that you can generate reports using a database that can achieve this very same
result if you want (once you learn about all of the programming that is involved).
Each database table column contains a similar type and classification of data within a given
database record structure, which is generally called a database field. This means that, conversely,
each row in your database table represents one entire database record. Generally when you are
writing your database record, you will write one entire row or record of data when you first add that
record. On the other hand, when you search a database for information, you are generally looking
through just one of the data table’s columns, or fields, for a specific piece of data or information.
Database columns (fields) can contain many different data types, such as numbers, text, or even
references to data stored somewhere else. It is important to note that each data field needs to contain
the same exact data type as the other data fields in that same column, as you can see in Figure 1 4- 1.
Figure 14-1. Basic overview of an RDBMS database (MySQL or SQLite)