Chapter Summary

Everyone needs to search for information. Computers make this job easier, but someone must set up and maintain the databases to ensure their integrity. There are many ways to search databases, and relational database management systems are a popular method. They are increasingly used as the foundation of the information system. They make it easy to share data among users while maintaining access controls. Equally importantly, the databases are easy to alter as the organization changes. Sophisticated databases can handle all the data types in use today, not just simple numbers and text.

It is relatively easy for users to obtain data using SQL or query-by-example tools. Because SQL is a recognized standard query language, it is worth remembering the basic elements of the SELECT command. The syntax is easy (SELECT columns, FROM tables, WHERE conditions, ORDER BY columns). Just remember that whenever you use more than one table, they must be joined by related columns.

An important step in databases is to design them correctly. The trick is to split the data into tables that refer to exactly one concept. Most organizations have a database administrator to help users create the initial database tables, define standards, establish access rights, and perform backups and testing. Once the tables have been defined, users can create input screens, reports, and views by using graphical tools to draw the desired items on the screen.

It is important to choose the right tool for each job. Databases excel at handling huge amounts of data and sharing it with other users. On the other hand, spreadsheets are designed to perform calculations and create graphs. One indication that a problem should be solved using a DBMS instead of a spreadsheet is that several tables of data are involved.

Every day, more information is stored in commercial databases. In many ways, they are becoming the libraries of the future. Almost any type of reference data you can imagine can be searched electronically. Just remember that you have to pay to access this data, so you have to design your search strategies carefully to save money.