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18.4.2.3. Creating Geometry Values Using MySQL-Specific Functions
MySQL provides a set of useful non-standard functions for
creating geometry WKB representations. The functions described
in this section are MySQL extensions to the OpenGIS
specification. The results of these functions are
BLOB values containing WKB representations
of geometry values with no SRID. The results of these
functions can be substituted as the first argument for any
function in the GeomFromWKB() function
family.
-
GeometryCollection(g1,g2,...)
Constructs a WKB GeometryCollection. If
any argument is not a well-formed WKB representation of a
geometry, the return value is NULL.
-
LineString(pt1,pt2,...)
Constructs a WKB LineString value from
a number of WKB Point arguments. If any
argument is not a WKB Point, the return
value is NULL. If the number of
Point arguments is less than two, the
return value is NULL.
-
MultiLineString(ls1,ls2,...)
Constructs a WKB MultiLineString value
using WKB LineString arguments. If any
argument is not a WKB LineString, the
return value is NULL.
-
MultiPoint(pt1,pt2,...)
Constructs a WKB MultiPoint value using
WKB Point arguments. If any argument is
not a WKB Point, the return value is
NULL.
-
MultiPolygon(poly1,poly2,...)
Constructs a WKB MultiPolygon value
from a set of WKB Polygon arguments. If
any argument is not a WKB Polygon, the
return value is NULL.
-
Point(x,y)
Constructs a WKB Point using its
coordinates.
-
Polygon(ls1,ls2,...)
Constructs a WKB Polygon value from a
number of WKB LineString arguments. If
any argument does not represent the WKB of a
LinearRing (that is, not a closed and
simple LineString) the return value is
NULL.
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