Database Design

External Links
databases.about.com∞
techonthenet.com∞
fabFORCE DBDesigner∞

Information about General Rules to database design

please edit, correct and complete this page...

First

Use one and only one primary key for each table.
Primary keys are unique and not nullable.
Primary key definition(s) from databases.about.com∞ and techonthenet.com∞. In short, each row in a table must have a unique identifier for that row. That identifier (the primary key) is often a single column, but may consist of multiple columns.
When the primary key of one table is stored in another table for the purpose of creating a relationship between those two tables, it is referred to as a Foreign Key.
Primary Key Values should not change. Some SQL engines support RI (Referential Integrity) rules with cascading updates. While this feature will allow for the changing of a primary key value, it is generally a bad idea to plan on editing a Primary Key Value. If you are sure the value of a Primary Key will never change, you can use this column value (Social Number). If you are not sure, use a internal counted number as the primary key and define the changeable value column as a unique constraint (product number).

please edit

fabFORCE DBDesigner∞ is a very good and free database designer. It is also possible to connect with PervasiveODBC