How to group-by to get MultiPoint/GeometryCollection in MySQL?
As Evan Carroll said in a comment: Unlike PostGIS, spatial aggregates are not available for MySQL.

The workaround left in a comment by danblack works:


  It looks like you want MultiPoint to be an aggregate function, which is isn't. You'll probably need something like ST_GeomFromText(CONCAT('MultiPoint(', GROUP_CONCAT(...), ')')), where ... gets an X Y string from fix_geom.