Defining a Primary Key for Web Databases

Every table in a relational database should have a primary key, and web databases are no exception. In web databases, however, you must follow the structure of SharePoint lists, which only allows the SharePoint ID field as the primary key. From a certain perspective, this makes defining a primary key in web databases quite simple-Access automatically creates the primary key field, the ID field, for you whenever you create a new web table. You cannot delete this field from your web table, but you can rename the ID field to something more to your liking, such as VendorID or InvoiceID.

If you're an experienced Access developer, you might find the ID primary key restriction to be very limiting. What if you want to create a multi-field primary key and set it to be unique, as you can for client databases? While it's true you cannot define a unique multifield primary key in SharePoint lists, you can achieve the same functionality by using table events, which is a new feature in Access 2010.