Select only records with region objects in MapBasic

Question

I am writing a program that finds overlapping objects. I can't perform the AreaOverlap() function on objects that don't enclose an area (e.g. text, points) as the result would be meaningless.

Is there a way to select only records that have objects that are regions?

I have a function that checks whether an object is a region (see below) so I could loop through the objects and check them one-by-one but it would be more efficient to do this as part of a select statement.

My example function:

Function IsObjectRegion(ObjAlias As Object) As Logical
  Do Case ObjectInfo(ObjAlias, OBJ_INFO_TYPE)
    Case OBJ_TYPE_REGION, 
         OBJ_TYPE_RECT, 
         OBJ_TYPE_ROUNDRECT, 
         OBJ_TYPE_ELLIPSE
      IsObjectRegion = True
    Case Else
      IsObjectRegion = False
  End Case
End Function

Update: my final, working code using Peter's method and my function:

Include "mapbasic.def"

Declare Sub main
Declare Function IsObjectRegion(ByVal ObjAlias As Object) As Logical

Function IsObjectRegion(ByVal ObjAlias As Object) As Logical
  Do Case ObjectInfo(ObjAlias, OBJ_INFO_TYPE)
    Case OBJ_TYPE_REGION, 
         OBJ_TYPE_RECT, 
         OBJ_TYPE_ROUNDRECT, 
         OBJ_TYPE_ELLIPSE
      IsObjectRegion = True
    Case Else
      IsObjectRegion = False
  End Case
End Function

Sub Main
  Select * from TargetTable Where obj into temp1 noselect
  Select * from temp where IsObjectRegion(OBJ) into results noselect
  Browse * from results
  Close table temp
End Sub

Answer 1

You could create you function like you have described above and use this directly in your Select statement:

Select * From MYTABLE
   Where IsObjectRegion(OBJ)
   Into __THESE__HAVE__AN__AREA NoSelect

Pretty clever

Answer 2

A simple approach would be as follows:

select *
from MYTABLE
where str$(obj) IN ("Region","Rectangle","Ellipse","Rounded Rectangle")
into q_RegionObjects