This topic describes the ST_LineMerge function. This function returns one or more LineString objects concatenated by a MultiLineString object.
Syntax
geometry ST_LineMerge(geometry amultilinestring);
Parameters
Parameter | Description |
---|---|
amultilinestring | The geometry object that you want to specify. |
Description
- The ST_LineMerge function supports MultiLineString objects and LineString objects. If you specify an object of another type, the ST_LineMerge function returns an empty GeometryCollection object.
- This function deletes the m coordinates of MultiLineString objects.
Examples
SELECT ST_AsText(ST_LineMerge(ST_GeomFromText('MULTILINESTRING((1 1,2 1),(2 1,2 2))')));
st_astext
-------------------------
LINESTRING(1 1,2 1,2 2)
(1 row)