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3. Attribute selection

The two entities on the previous page are shown again below

You may remember from the 'keys' section that it's important to have a unique identifier for every item in the database.

So the first attribute we'll add is that identifier. For products, this will be 'ProductID'. for Suppliers, 'SupplierID'. These will be acting as the primary keys for the entities, so they'll be underlined to show their importance.

Next, we'll fill in some other useful attributes for each entity, 'Description' and 'Price' for products, and 'Name', 'Telephone', 'Address', and 'Post Code' for suppliers.


Now that the entities each have their set of attributes, you could use them to create a table. The name of the entitity is the name of the table, and each of the attributes is a field within that table. Let's add a few records for each, to demonstrate:

An important note is that the entity is not the table itself. The entity is the description of the table (the table name, the fields, but not the records themselves).


Challenge see if you can find out one extra fact on this topic that we haven't already told you

Click on this link: What is an attribute of an entity