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.
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.
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.