Oracle Spatial User's Guide and Reference - InfoLab

SDO_UTIL.TO_GMLGEOMETRY
Examples
Any circular arcs or circles must be densified (using the SDO_GEOM.SDO_BUFFER
or SDO_GEOM.SDO_ARC_DENSIFY function) before being passed to the TO_
GMLGEOMETRY function. (See the Examples section for an example that uses
SDO_ARC_DENSIFY with the TO_GMLGEOMETRY function.)
Label points are discarded. That is, if a geometry has a value for the SDO_POINT
field and values in SDO_ELEM_INFO and SDO_ORDINATES, the SDO_POINT is
not output in the GML fragment.
The SDO_SRID value is output in the form srsName="SDO:". For
example, "SDO:8307" indicates SDO_SRID 8307, and "SDO:" indicates a null
SDO_SRID value. No checks are made for the validity or consistency of the SDO_
SRID value. For example, the value is not checked to see if it exists in the
MDSYS.CS_SRS table or if it conflicts with the SRID value for the layer in the
USER_SDO_GEOM_METADATA view.
Coordinates are always output using the tag and decimal='.',
cs=',' (that is, with the comma as the coordinate separator), and ts=' ' (that is,
with a space as the tuple separator), even if the NLS_NUMERIC_CHARACTERS
setting has ',' (comma) as the decimal character.
The GML output is not formatted; there are no line breaks or indentation of tags. To
see the contents of the returned CLOB in SQL*Plus, use the TO_CHAR() function or
set the SQL*Plus parameter LONG to a suitable value (for example, SET LONG
40000). To get formatted GML output or to use the return value of TO_
GMLGEOMETRY in SQLX or Oracle XML DB functions such as XMLELEMENT,
use the XMLTYPE(clobval CLOB) constructor.
The following example returns the GML fragment for the cola_b geometry in the
COLA_MARKETS table. (The example uses the definitions and data from
Section 2.1.)
-- Convert cola_b geometry to GML fragment.
SELECT TO_CHAR(SDO_UTIL.TO_GMLGEOMETRY(shape)) AS GmlGeometry
FROM COLA_MARKETS c WHERE c.name = 'cola_b';
GMLGEOMETRY
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