Sql – Best way to do multiple table associations in a LINQ dbml file

Take advantage of the namespace settings. You can get to it in properties from clicking in the white space of the ORM.

This allows me to have a Users table and a User class for one set of business rules and a second (but the same data store) Users table and a User class for another set of business rules.

Or, break up the library, which should also have the affect of changing the namespacing depending on your company's naming conventions. I've never worked on an enterprise app where I needed access to every single table.

Check your Error List page. You might have something like the following in there:

DBML1062: The Type attribute '[ParentTable]' of the Association element 'ParentTable_ChildTable' of the Type element 'ChildTable' does not have a primary key. No code will be generated for the association.

In which case all you should need to do is make sure that both tables have a primary key set and re-save the dbml file. This will invoke the custom tool, which will in turn update the designer.cs file and create code for the association.