The database chart shown above was drawn with RFFlow using the Database
Design Stencil. This database has three tables, Employees, Dependants, and
Department.
In the Employees table, the primary key is the Employee ID. The other fields
are the usual name, address, etc. Each employee may have several dependants,
so the Dependants table has a many to one relationship to the Employees table.
The Employee ID relates these two tables.
A database with multiple tables that are related is called a relational
database.
A department will hopefully have many employees so the Department table is
related to the Employee Table in a one to many relationship using the
Department Code. The Department Code is the primary key in the Department
Table. The Department Code is not a primary key in the Employees table so it
is referred to as a foreign key and labeled differently.
The chart above also shows some index fields. These are used if you regularly
sort data in tables by the same field. It speeds up searches.
This database chart uses a modern set of
symbols.
- Primary key
- Data
- Foreign key
- Index
- One to many
RFFlow also includes the traditional symbols used in drawing database
diagrams. If there are any symbols that we don't have, contact us and we can
add them in the next RFFlow upgrade.