Understanding Database Concepts

A database is an organized collection of related information. For example, if you were to jot down on a piece of paper a list of all the movies you watched last year and the date you watched each one, you would have the paper equivalent of a database. All the informaton would be related , and it would probably be organized in columns and rows.

The most basic element of a database is the table , which is a set of information arranged in records (rows) and fields (columns). Every database has at least one table, but databases can include dozens or even hundreds of tables of related data. For example, a roofing company s client database might contain a table that assigns clients an ID number and lists their names and addresses. Another table in the database might list the client IDs and credit references. Still another table might summarize account transactions for the last three years by client ID. All the tables contain information about the clients, but different information is related by the client ID in each table. All the information could be kept in just one table, but if only a few clients have active accounts, the part of the table devoted to account transactions would have only a few entries. So it s better to break the database into separate but related tables.

As we said, tables are the basic building blocks of a database. In addition to tables, a database can include queries, forms, reports , and other components , all of which allow you to view and manipulate database information. In this and the next chapter, you will create a database for Tip Top Roofing that includes several of these components. By the time you finish these chapters, you should be comfortable creating a database, filling it with information, and manipulating that information. As your experience and knowledge grow, you will discover many other ways you can use Access. You can, for example, create web pages directly from Access or use a programming language to create dynamic web pages from an Access database in response to selections or input from users all over the world.

Fields and records

The basic structure of a database is a combination of fields and records. Each field contains bits of similar information ”for example, all the phone numbers in the phone book. Each record contains all the bits of information about a particular item such as a person, product, or event ” for example, the name , address, and phone number for one person in the phone book.