Relations in Access

[Genom]

Hi;
I want to ask you about relations in MS Access. How can I use them efficiently and how can they help in my programs (in vb.net)? I use SQL commands. Are there such things in MS SQL too?

[sparbag]

Hello Genom,

The question asked has a huge subject base but the basics are the database management system of your database when correctly designed to the needs of the information needed out will minimise the programming of the front end/application tier.

When I started University I was pointed to this site:
http://www.utexas.edu

In database terms a relation is a table and a database has many relations. the relationship between these relations relies upon referential integrity.
Referential integrity is created by using the primary key to foreign key constraint (cardinality). The check constraint (in Access this would be setting desired values to the field), the partiality constraint (a relation can have 0 or more child relations where 0 can exist [ NULL ] . Also is the cascading deletions and updates where setting them correctly takes the work away from the programmer.
Management of the primary keys to allow for the database to grow. Autonumber is such an easy alternative to creating a candidate primary key, or even a composite primary key.
Understand also that if a field is part of a primary key in one table then it must also exist as a primary key of its own table.

You have me rambling

Perhaps if you could offer more information to what design you were considering. There is even a web site that offers pre-built relational schemas for users to copy.

Kind regards

Stev