What is a Database?

Databases are designed to offer an organized mechanism for storing, managing and retrieving information. They do so through the use of tables. If you’re familiar with spreadsheets like Microsoft Excel, you’re probably already accustomed to storing data in tabular form. It’s not much of a stretch to make the leap from spreadsheets to databases. Let’s take a look. 

Database Tables

Just like Excel tables, database tables consist of columns and rows. Each column contains a different type of attribute and each row corresponds to a single record. For example, imagine that we were building a database table that contained names and telephone numbers. We’d probably set up columns named “FirstName”, “LastName” and “TelephoneNumber.” Then we’d simply start adding rows underneath those columns that contained the data we’re planning to store. If we were building a table of contact information for our business that has 50 employees, we’d wind up with a table that contains 50 rows. 

Databases and Spreadsheets

At this point, you’re probably asking yourself an obvious question – if a database is so much like a spreadsheet, why can’t I just use a spreadsheet? Databases are actually much more powerful than spreadsheets in the way you’re able to manipulate data. Here are just a few of the actions that you can perform on a database that would be difficult if not impossible to perform on a spreadsheet:

•  Retrieve all records that match certain criteria
• Update records in bulk
• Cross-reference records in different tables
• Perform complex aggregate calculations

Definition

• A database is a collection of information organized into interrelated tables of data and specifications of data objects.

• A table in a relational database is a predefined format of rows and columns that define an entity.

• Database tables are composed of individual columns corresponding to the attributes of the object.

• In a relational database, a row consists of one set of attributes (or one tuple) corresponding to one instance of the entity that a table schema describes.
  

• A single data item related to a database object. The database schema associates one or more attributes with each database entity.

• A database record consists of one set of tuples for a given relational table. In a relational database, records correspond to rows in each table.