Tables, Columns and Rows

What is a database table?

Information in a database is organized in tables:

  • A database contains several tables.
  • Each table contains information about persons or things of the same nature.
Example: you are storing various types of information about your firm in a database. Information about customers would be stored in one table. Information about bills would be stored in another table.

What are rows in a database table?

A table contains information about several persons or things.
This information is divided into several rows. Each row contains information directly related to one of these people or things.

Example: Arun Rampal is a customer. In the table containing information about customers:

  • his name, email and phone number would be stored in one row.
  • another customer’s name, email and phone number would be stored in another row.

What are columns ?

The information about a thing or a person can be composed of many elements.
In the previous example, we store not only the customer’s name, but also his email, and phone number.

Each element (name, email, phone) is stored in a separate place called a column. In the previous example, there will be a column to put the customers’ names, another to put their emails, another to put their phone numbers.

Note that Arun Rampal’s phone number is in the same column as John Doe’s phone number.

There is one column to store all phone numbers. How do I know which phone number is belonging to Arun Rampal?

In the row dedicated to Arun Rampal, there is only one element in the column “phone number”. This element is called a field. All other phone numbers (John Doe’s and Eric Doucet’s phone numbers) are stored on different rows.
 

To test your understanding of this lesson, take the Database, Columns and Rows Quiz. You can also go to the next lesson about DBMS and RDBMS.
 
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Last udpated: September 10, 2017
Created: April 22, 2014