Possible values for column: Read from another column on page load#487

Could this be a way to circumvent the limitation of not being able to use multi-value selectbox with foreign key columns..?

Preferably, the source column could be from any table or be any SQL column, just not using the foreign key approach, but still offering similar user experience.

Could even be a column from the current table, in those use-cases where this makes sense, like the one mentioned below.

If there could be a possible problem using multi-value selectbox when the value in the source column gets modified or deleted, I think those situations could be handled just by ignoring any mismatch, so the selected values of course stay as they are stored until a user modifies them, selecting whatever values are currently available.
Most likely in a major share of the use-cases the source column would only keep getting new values added anyway, and it can be noted in the documentation that this is what the feature is designed for.

In the future I’m probably starting to get quite desperate to have a multi-value selectbox somehow for my “compatible with another product” implementation… otherwise I just have to set a hard limit for the number of compatible products that can be stored, and add the same number of columns for them, even if usually those columns are left completely empty. Not the optimum solution.