Syntax
------

MultiLineString(ls1,ls2,...)

Description
-----------

Constructs a WKB MultiLineString value using WKB LineString arguments. If any
argument is not a WKB LineString, the return value is NULL.

Example
-------

CREATE TABLE gis_multi_line (g MULTILINESTRING);
INSERT INTO gis_multi_line VALUES
 (MultiLineStringFromText('MULTILINESTRING((10 48,10 21,10 0),(16 0,16 23,16
48))')),
 (MLineFromText('MULTILINESTRING((10 48,10 21,10 0))')),
 (MLineFromWKB(AsWKB(MultiLineString(LineString(Point(1, 2), 
  Point(3, 5)), LineString(Point(2, 5),Point(5, 8),Point(21, 7))))));

URL: https://mariadb.com/kb/en/multilinestring/