Now that PHPMaker supports multiple parents in User ID security, it would also make sense to support creating master/detail joins in which a detail record can have multiple parents. The find_in_set operator could be used to create a join on a field containing comma-separated values.This feature could be implemented easily and seamlessly. If the user creates a join between an integer field and a varchar field, PHPMaker could assume the varchar is a comma-separated list. In this instance, instead of using the = operator, it would use the find_in_set operator, when creating the join.
I have a specific use case for a messaging system, where each message has a sender ID and a receipient ID. When viewing a user as an admin, I want to be able to view all messages sent by AND received by the user. Currently, I’m accomplishing this with a cumbersome workaround that generates a custom filter in the Recordset_Selecting event. It would be much cleaner if I could simply join the user ID field in the parent record to the user_ids field in the detail record. This user_ids field would be a comma-separated list, containing the sender and recipient IDs for the message.