A typical database application consists of three parts: a user interface, a database backend or server, and some software to link these two parts.
One of the reasons people often don't realize that databases are virtually everywhere is that the access to databases goes through a user interface that does not look like a database interface. Take for instance the new train ticket vending machines. Through a touch screen you enter into a dialog where you select your destination, then optionally the departure station, and then additional parameters like one way or return ticket, full price or reduced price, valid for today or for any future date, the number of tickets, and then the machine presents the price and asks how you wish to pay. What most user's do not realize is that a number of database operations are performed, including:
Upon selecting a letter, the list of stations starting with that letter is retrieved and presented.
After selecting the options, the price for the trip is retrieved. (It can also be calculated but from the total distance travelled, but then the length of the trip needs to be retrieved.)
The payment initiates the issuing of a train ticket, and this completes the database transaction.
In the course Databases 1 we concentrate on the query or retrieval operations that are hidden behind the user-interface. We will learn how to translate natural language (Dutch or English) to database query languages, and how to read them back. Once we master this skill, the remaining effort to complete a database application may still be a lot of work, but it is essentially trivial.