Lesson 1ª

 

 

 

 

 

 

 

What is ACCESS?

In a few words, it is a program to create and manage databases.

What is a database? This answer is as easy as the previous one.

Have you ever tried to look for a telephone number in a phonebook? Of course you have! First, you need to take the wide phonebook from wherever you live. This is nothing more than a printed "database". In its pages, you see every recorded telephone number. However, you don't read all of them one by one. We usually "filter" the guide looking for a specific group and ignoring the rest. Even so, the volume of the pages is still large for us to read entire pages. Luckily, someone decided to write a column with the names of the people along with their address.

Each page is a "table", in which each column is a "field". The tables in the guide are organized, or "indexed", following alphabetical order in the last name or surname field. In other words, the last name field is the "key" of the table.

Luckily, the telephone guide "database" is organized in this manner. Thus, just by knowing the City, the Last Name and the Address, we can quickly find any telephone number.

However, there are other way to "index" a table, for example, by means of the "Address" field. In this case, with the name of the street, avenue, road, etc. we would be able to know the names of the people living on it as well as their phone numbers. We could also use the field "telephone number" in this type of guide to perform a "reverse look up".

Through this simple example, we now know what a database, a filter, a table, the fields, indexes, keys etc. are. With a little imagination, we can foresee the possibilities a program should handle, organize and index large databases for us, such as telephone guides, library books, patients medical history, invoices for an enterprise, etc.