Recently I encountered a situation similar to https://www.llblgen.com/tinyforum/Messages.aspx?ThreadID=16966

What I did is explicitly passing in a no use property of the entity to trick it(linq expression parser?) not to treat the function as in memory

Some code snippet of mine:

public static Object GeomFromGeojson(string geojson, Object o[This is My Trick]) { return null; }

this.Add(new FunctionMapping(typeof(GeomFuncs), "GeomFromGeojson", 2, "ST_GeomFromGeoJSON({0})", "", ""));

linqMetaData.SomeEntity.Where(c => GeomFuncs.STContains(c.Area, GeomFuncs.GeomFromGeojson("{\"type\":\"Point\",\"coordinates\":[-87.22217, 30.44195]}", c.Id[This is My Trick])))

Without the tricking second parameter, the whole GeomFromGeojson will be passed in as null, which is result of the function definition, resulting unexpected result.

So, my question is, except this workaround of mine, is there a better way to make it work?

That's the workaround, available. The logic looks for a dependency to decide whether it would be executed in-memory or mapped to a db function.

Indeed, what Walaa says: if it can't determine some DB related element is involved it will assume in-memory code and will run it as in-memory, as in Linq queries you can mix both.

Got it. Thank you. You guys are helpful as always.