-- This example demonstrates how to use the SE_CreateSrtext function
-- to generate the OpenGIS Well-Known Text for a spatial reference
-- coordinate system.  This text string can be used in the srtext column
-- of a spatial_references table entry.
--
-- SE_CreateSrtext will return the text string associated with the numeric
-- constants in the ESRI Projection Engine definitions header file.
-- This file is included with the Informix Spatial DataBlade and can be
-- found in $INFORMIXDIR/extend/spatial.<version>/include/pedefs.h.
--
-- Note that not all constants in this file define coordinate systems;
-- some constants define coordinate system "building blocks" such as
-- units of measure, spheroids, datums, projections, etc.  SE_CreateSrtext
-- will still return the text strings for these components, but they
-- cannot be used in the srtext column of a spatial_references entry.
-- Only the PE_GCS_xxx and PE_PCS_xxx constants define full coordinate
-- systems.

-- Example #1: Clarke 1866 Ellipsoid.  This by itself is not a 
-- coordinate system!

EXECUTE FUNCTION SE_CreateSrtext(7008);

-- Example #2: North American Datum 1983, unprojected:

EXECUTE FUNCTION SE_CreateSrtext(4269);

-- Example #3: UTM zone 17, northern hemisphere, WGS 1984 datum:

EXECUTE FUNCTION SE_CreateSrtext(32617);


-- Tip: You can transfer the output of SE_CreateSrtext directly into
-- the spatial_references table with the following SQL statement.
-- This example assumes that srid 1000 already exists.

UPDATE spatial_references 
   SET srtext = SE_CreateSrtext(4269) WHERE srid = 1000;