This is Chapter 8 of Getting Started with OpenOffice.org 3.x, produced by the
OOoAuthors group. A PDF of this chapter is available from
Documentation at OpenOffice.org.
A data source, or database, is a collection of pieces of information that can be accessed or managed by OpenOffice.org (OOo). For example, a list of names and addresses is a data source that could be used for producing a mail merge letter. A shop stock list could be a data source managed through OOo.
||OpenOffice.org uses the terms "Data Source" and "Database" to refer to the same thing, which could be a database such as MySQL or dBase or a spreadsheet or text document holding data.
This chapter covers creating a database, showing what is contained in a database and how the different parts are used by OOo. It also covers using the Base component of OOo to register other data sources. A data source can be a database, spreadsheet, or text document.
Data sources are only introduced in this chapter. For more detailed information about the use of databases, see the Database Guide (not yet written).
||OOo Base uses the HSQL database engine. All of the files created by this engine are kept in one zipped file. The database forms are included in this zipped file.
A database consists of a number of fields that contain the individual pieces of data. Each table of the database is a group of fields. When creating a table, you also determine the characteristics of each field in the table. Forms are for data entry into the fields of one or more tables associated with the form. They can also be used for viewing fields from one or more tables associated with the form. A query creates a new table from the existing tables based upon how you create the query. A report organizes the information of the fields of a query in a document according to your requirements.
||The database in OOo requires Java Runtime Environment (JRE). If you do not have it on your computer, you can download it from
www.java.com and install it following the instructions on the site. It should be Java 5.0 or higher. In OOo, use Tools > Options > OpenOffice.org > Java to register Java. Windows' version of JRE can not be used, while there are other versions that can.
Base creates relational databases. This makes it fairly easy to create a database in which the fields of the database have relationships with each other.
For example: Consider a database for a library. It will contain a field for the names of the authors and another field for the names of the books. There is an obvious relationship between the authors and the books they have written. The library may contain more than one book by the same author. This is what is known as a one-to-many relationship: one author and more than one book. Most if not all the relationships in such a database are one-to-many relationships.
Consider an employment database for the same library. One of the fields contains the names of the employees while others contain the social security numbers, and other personal data. The relationship between the names and social security number is one-to-one: only one social security number for each name.
If you are acquainted with mathematical sets, a relational database can easily be explained in terms of sets: elements, subsets, unions, and intersections. The fields of a database are the elements. The tables are subsets. Relationships are defined in terms of unions and intersections of the subsets (tables).
To explain how to use a database, we will create one for automobile expenses. In the process, we will be explaining how a database work.