Relational databases

 

Practical definition:  Organized collection of data stored in logically related tables.

 

Example: 

 

1. Open the Northwind training database (C:\TEMP\NorthwindTraining.mdb in 116 PHTC).

 

(NOTE:  For practice on your own computer, make a copy of the Northwind database before starting; or start in a blank new database and import the Northwind tables you  need.)

 

2.  Close the splash screen and the Main Switchboard form.

3.  Open  the Products table in Datasheet view.

4.  Change to Design view (View button) and find the primary key.

5.  Check for any other indexed columns (fields):  View / Indexes.

6.  Close the table

 

 

Referential integrity constraints:  Primary / foreign key relationships or rules defined using SQL or vendor extensions that ensure data integrity and consistency throughout all tables in the database.

 

 

Example:  Relationships diagram in the Northwind database

 

1.  Click the Relationships button or choose Tools / Relationships.

2.  Find the Products table and its related table or tables.

3.  Note the primary key and two foreign keys in the Products table.