and I'm tempted to make a table to store member-organization entries. But unfortunately there are several hundred queries in the app and this is nontrivial to w

and I'm tempted to make a table to store member-organization entries. But unfortunately there are several hundred queries in the app and this is nontrivial to write, much less exhaustively test It is possible to normalize the database and still present the denormalized form to the app using MySQL views (I'm assuming MySQL here). You have your member table, organization table, and a member_organizaion join table with all your foreign key constraints, and you create a view as a select join.