About Database Tables

Database tables will most likely be the area you'll become most familiar with after working with databases for a while. Now, before we go ahead and start adding tables to our new database, let's have a look at what a database table actually is.

What is a Table?

In database terms, a table is responsible for storing data in the database. Database tables consist of rows and columns.

In the following example, the second row is highlighted in black:

In the next example, the second column is highlighted in black. This column has been given a name of "FirstName":

A row contains each record in the table, and the column is responsible for defining the type of data that goes into each cell. Therefore, if we need to add a new person to our table, we would create a new row with the person's details.

Creating a Database

With database management systems, many tasks can be done either via programatically or a user interface. Creating databases is no exception.

Option 1: Programatically

Many database administrators (DBAs) use Structured Query Language (SQL) to perform many of their database tasks. To enter SQL, you need to open an interface that allows you to enter your code. For example, if you use SQL Server, you would normally use Query Analyzer.

The following example is the basic code for creating a new database. Parameters can be added to this example if your requirements are more specific.

Code

Note: This example assumes you know how to use your database system to run scripts like this. If you don't you, will probably find it easier to use the user interface method (below).

Option 2: User Interface

Most database systems make it very easy to create a database via a user interface. Generally, it's just a matter of selecting an option from a menu, then providing a name for your database.

The following examples demonstrate how to create a database in Microsoft Access.

1. From the "File" menu, click on "New Database":
   
2. Choose "Blank Database". (MS Access also gives you the ability to choose from a template, but we'll just use a blank database here):
   
3. Choose a location to save the database:
   

Your New Database

Once you've completed the above tasks, you should see a blank database, like this:

We know this database is blank because it doesn't have any tables. If it did, you would see these tables in the middle pane of the table tab. Now that we have our blank database, we can start adding some tables.

Database Management Systems

A Database Management System (DBMS), is a software program that enables the creation and management of databases. Generally, these databases will be more complex than the text file/spreadsheet example in the previous lesson. In fact, most of today's database systems are referred to as a Relational Database Management System (RDBMS), because of their ability to store related data across multiple tables.

Some of the more popular relational database management systems include:

• Microsoft Access
• Filemaker
• Microsoft SQL Server
• MySQL
• Oracle

Throughout this tutorial, you will become familiar with some of the key concepts of database management systems. These include:

• Database creation
• Tables
• Adding data to your database
• Querying a database
• Relational database design

What Does a Database Management System Look Like?

Different database management systems look different, but generally, there are a number of common features that you'll usually see across most of them.

Microsoft Access

This is the main screen you'll see when opening up Access to view an existing database. The outer part is the database management system and it's menu, the middle part is the actual database. In this example, the database is called "dateSite" and has 20 tables. If you were to open a different database, the name of the database would be different and you would see different tables, but the available options would be the same (i.e. Tables, Queries, Forms, Reports, Macros, Modules, Open, Design, New).

Some of these options are common across all database management systems. All database systems allow you to create tables, build queries, design a new database, and open an existing database.

Microsoft SQL Server

Microsoft SQL Server is a more robust database management system than Access. While Access is better suited to home and small office use, SQL Server is more suited to enterprise applications such as corporate CRMs and websites etc.

The above screen is what you see when you open SQL Server through Enterprise Manager. Enterprise Manager is a built-in tool for managing SQL Server and its databases. In this example, there are 6 databases. Each database is represented down the left pane, and also in the main pane (with a "database" icon).

Which Database System to Use?

If you are using a database for home or small office use, Microsoft Access or Filemaker should be fine. If you need to create a database driven website, then you're better off using a more robust system such as SQL Server, Oracle, or MySQL.

The examples in this tutorial use Microsoft Access. If you don't have Microsoft Access, you should still be able to follow the examples. The tasks we perform are the same tasks you would need to perform regardless of which database management system you use. The key goal with this tutorial is to provide you with an overview of what is involved in creating and maintaining a database.

What is a Database?

A database is a collection of data. That may sound overly simplistic but it pretty much sums up what any database is.

A database could be as simple as a text file with a list of names. Or it could be as complex as a large, relational database management system, complete with in-built tools to help you maintain the data.

Before we get into dedicated database management systems, let's start with the basics - let's look at a simple text file example.

Text File

Imagine we have a text file called "Individual.txt", and that the contents look like this:

We could use this information to do things such as send an email to everyone on our list. We could do this because, due to the way we designed the list, we know that each row contains a different individual, and the information on that row is related to that individual. Also, the items in each row are separated by commas. Therefore, we know that the email address next to "Homer" is his email address. We could also call each row a record. Therefore, we currently have 4 records in our database.

With a small list like this, a text file may serve our purposes perfectly.

Spreadsheet

Another option would be to store it in a spreadsheet using spreadsheet software (for example, Microsoft Excel). That way, we could do some extra things with our list (such as format it, or sort by first name/surname etc).

A spreadsheet program like Excel makes these tasks relatively easy to do. Also, programs like Excel organize the data into rows and columns, making your data easier to comprehend. Something like this:

Database Software

A better option would be to store the data in a database table using specialized database software, such as Microsoft Access. Something like this:

So What's the Difference?

You may be wondering what the difference is between the last two examples (Excel vs Access). After all, both examples have the data organized into rows and columns.

There are many differences between spreadsheet software and database software. The rest of this tutorial will show you why database software is a much better option for creating databases.