I can't get my head around this. I understand that using primary keys they link together tables within Access but what are the benefits of this?
I wonder because I am creating a system where I want the data values from one table to be shown in another table.. is this the purpose of it?What is the point of entity relationships?
The primary reason is to reduce data duplication.
Imagine a product database where someone had to fill in the product name every time a sale was registered.
A foreign key allows the name to be stored once in a table and a key is used to refer to the product name.
The process of removing the duplicates is called normalisation and wikipedia has a good page here:
http://en.wikipedia.org/wiki/Database_no鈥?/a>
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