A database’s primary purpose is to store and extract information. Information can be obtained from a database immediately after you enter the data or days, weeks, or even years later. Of course, retrieving information from database tables requires knowledge of how the database is set up.
For example, printed reports are often filed in a cabinet, arranged by date and by a sequence number that indicates when the report was produced. To obtain a specific report, you must know its year and sequence number. In a good filing system, you may have a cross-reference book to help you find a specific report. This book may have all reports categorized alphabetically by type of report and, perhaps, by date. Such a book can be helpful, but if you know only the report’s topic and approximate date, you still have to search through all sections of the book to find out where to get the report.
Unlike manual databases, computer databases like Microsoft Access easily obtain information to meet virtually any criteria you specify.
This is the real power of a database—the capacity to examine the data in more ways than you can imagine. Queries, by definition, ask questions about the data stored in the database. Most queries are used to drive forms, reports, and graphical representations of the data contained in a database.
The word query comes from the Latin word quærere, which means “to ask or inquire.” Over the years, the word query has become synonymous with ...