How a databse works

Now that you are familiar with the basic concepts of field and record, let's see how a database actually functions. For this purpose we could think of a program that can manage students' data in a school.

First we should arrange all the personal information of each student in a table (A): name , address, telephone number, etc. In another table (B) there might be the data concerning the class situation: class, teachers, subjects. And a third table (C) would include the students' grades, credits or other proficiency-related information.

The three distinct tables must then be put together. Each of the tables contains at least one indexed field that links together the tables you have created. After having filled the various fields with data, you can query the database and get the information you want. For example you can call up the school record of a single student by selecting the proper fields (name, subjects, grades).

What you can do with a database is to search, sort and query. Using our example above, searching means that you can ask the program to call up a student's name. Sorting could be something like arranging the students' names in alphabetical order. Finally, you can query the database asking it to show only specific data, e.g. name, address and telephone number of the students who have a grade higher than 8 in History.