I've created a custom entity called "Test", derived from Base but with an additional integer field called "value".

Inside the entityDefs/Test.json, I've added a "notStorable" bool as below:

"isBelowZero": {
            "type": "bool",
            "readOnly": true,
            "notStorable": true,
            "select": "(value < 0)",
            "orderBy": "isBelowZero {direction}"
However, when I add this field to the "Search Filters" in the layout, any attempt to filter using this results in a 500 error.

In the above instance, I get a "Column not found: 1054 Unknown column 'test.is_below_zero' in 'where clause';" error but I'm not wanting to filter against a database column.

No matter how I change the syntax, I always get this 500 error. If I change the type to a "float" and do a comparison to zero, it works fine but never works with a bool.

If anyone could point me in the direction of a back-end change which would allow me to populate this field when the record is pulled from the database, that would be great.

As a side note, this is a very primitive example of what I'm trying to do - the actual computation in my real-world "select" is much more complex and pulls data from other tables in order to get to a TRUE or FALSE value.