The SE_AsKML() function

The SE_AsKML() function returns the Keyhole Markup Language (KML) representation of an ST_Geometry spatial type.

Typically, you use the SE_AsKML() function to retrieve the KML representation of a spatial primitive from the server and send it to a client, as in:

SELECT SE_AsKML(geomcol) FROM mytable

The return type of the SE_AsKML() function is defined as LVARCHAR. You can write user-defined routines (UDRs) in C or SPL to extend the functionality of the existing spatial data type functions.

Syntax

SE_AsKML(p ST_Geometry)

Return type

ST_Geometry

Example

In this example, the SE_AsKML() function converts the location column of the table mytable into its KML description.

CREATE TABLE mytable (id integer, location ST_Point);

INSERT INTO mytable VALUES( 
   1, ST_PointFromText('point (10.02 20.01)', 1000) 
);

SELECT id, SE_AsKML(p1) FROM point_t ORDER BY id asc;
id            100_xy
<Point><coordinates>10.02,20.01</coordinates></Point> 

CREATE TABLE line_t (id integer, p1 ST_LineString);

INSERT INTO line_t VALUES(
  1,
  ST_LineFromText('linestring (0.0 0.0,0.0 1.0,1.0 0.0,1.0 1.0)',1000)
);
1 row(s) inserted.


INSERT INTO line_t VALUES(
  2,
  ST_LineFromText('linestring z (0.0 0.0 0,0.0 1.0 1,1.0 0.0 1,1.0 1.0 1)',1000)
);
1 row(s) inserted.

INSERT INTO line_t VALUES(
  3,
  ST_LineFromText('linestring m (0.0 0.0 0,0.0 1.0 1,1.0 0.0 1,1.0 1.0 1)',1000)
);
1 row(s) inserted.


SELECT id, SE_AsKML(p1) FROM line_t ORDER BY id ASC;
id            1
<LineString><coordinates>0,0 0,1 1,0 1,1</coordinates></LineString> 
id            2
<LineString>
  <coordinates>0,0,0 0,1,1 1,0,1 1,1,1</coordinates>
</LineString> 
id            3
<LineString><coordinates>0,0 0,1 1,0 1,1</coordinates></LineString>