/ modules / paradigms / Spatial_InformixMapInfo.py 

 SYNOPSIS

     Spatial_InformixMapInfo (table, idColumn, footprintColumn, cardinality)

         table
             A table to query, e.g., "holding".

         idColumn
             The table's object identifier column (i.e., the column
             to be selected), e.g., "holding_id".

         footprintColumn
             The table's footprint column (i.e., the column against
             which the constraint is to be placed), e.g.,
             "footprint".

         cardinality
             A Cardinality object representing the cardinality of
             'table' with respect to 'footprintColumn'.

 DESCRIPTION

     Translates a spatial constraint to an Informix MapInfo function
     call of the form:

         SELECT idColumn FROM table
             WHERE function(footprintColumn, targetExpression)

     where 'function' is either 'ST_Contains', 'ST_Within', or
     'ST_Overlaps', depending on the constraint operator.

     This paradigm assumes that MapInfo's first (X) coordinate is
     longitude in degrees east of the Greenwich meridian and in the
     range [-180,180], and that the second (Y) coordinate is latitude
     in degrees north of the equator and in the range [-90,90].

     'targetExpression' is a string that can take any of several
     forms.  Depending on the query region, it may describe a point,
     a box, a pair of (geodetically adjacent) boxes, a vertical line
     segment, a horizontal line segment, a pair of collinear
     (geodetically adjacent) horizontal line segments, or a polygon.

     The discontinuity at the +/-180 meridian is handled correctly,
     but the discontinuities at the poles are not.

     Exceptions thrown:

         none

 AUTHOR

     Greg Janee
     gjanee@alexandria.ucsb.edu

 HISTORY

     $Log: Spatial_InformixMapInfo.py,v $
     Revision 1.2  2003/04/16 18:32:10  valentin
     updated to latest translator code

     Revision 1.1  2002/10/22 02:58:09  gjanee
     Initial revision