Database Design Basics (Cont.)

The Design Process
The design process consists of the following steps:
  1. Determining the purpose of your database
    This helps prepare you for the remaining steps.

  2. Finding and organizing the information required
    Gather all of the types of information you might want to record in the database, such as product name and order number.

  3. Dividing the information into tables
    Divide your information items into major entities or subjects, such as product or order. Each subject then becomes a table.

  4. Turning information items into columns
    Decide what information you want to store in each table. Each item becomes a field, and is displayed as a column in the table. For example, an employee table might include fields such as last_name and hire_date.

  5. Specifying primary keys
    Choose each table’s primary key. The primary key is a column that is used to uniquely identify each row. An example might be productID or orderID.

  6. Setting up the table relationships
    Look at each table and decide how the data in one table is related to the data in other tables. Add fields to tables or create new tables to clarify the relationships, as necessary.

  7. Refining your design
    Analyze your design for errors. Create the tables and add a few records of sample data. See if you can get the results you want from your tables. Make adjustments to the design, as needed.

  8. Applying the normalization rules
    Apply the data normalization rules to see if your tables are structured correctly. Make adjustments to the tables, as needed.



      How many software engineers does it take to change a lightbulb? None.    
      That’s a hardware problem.