Oracle 5.0 Reference Manual page 1011

+-------------------------------------------------------+
| AsText(Envelope(GeomFromText('LineString(1 1,2 2)'))) |
+-------------------------------------------------------+
| POLYGON((1 1,2 1,2 2,1 2,1 1))
+-------------------------------------------------------+
•
GeometryType(g)
Returns as a binary string the name of the geometry type of which the geometry instance
member. The name corresponds to one of the instantiable
mysql> SELECT GeometryType(GeomFromText('POINT(1 1)'));
+------------------------------------------+
| GeometryType(GeomFromText('POINT(1 1)')) |
+------------------------------------------+
| POINT
+------------------------------------------+
•
SRID(g)
Returns an integer indicating the Spatial Reference System ID for the geometry value g.
In MySQL, the SRID value is just an integer associated with the geometry value. All calculations are
done assuming Euclidean (planar) geometry.
mysql> SELECT SRID(GeomFromText('LineString(1 1,2 2)',101));
+-----------------------------------------------+
| SRID(GeomFromText('LineString(1 1,2 2)',101)) |
+-----------------------------------------------+
|
+-----------------------------------------------+
The OpenGIS specification also defines the following functions, which MySQL does not implement:
•
Boundary(g)
Returns a geometry that is the closure of the combinatorial boundary of the geometry value g.
•
IsEmpty(g)
This function is a placeholder that returns 0 for any valid geometry value, 1 for any invalid geometry
value or NULL.
MySQL does not support GIS
•
IsSimple(g)
In MySQL 5.0, this function is a placeholder that always returns 0.
The description of each instantiable geometric class given earlier in the chapter includes the specific
conditions that cause an instance of that class to be classified as not simple. (See
"The Geometry Class
12.16.5.2.2. Functions
Point
A consists of X and Y coordinates, which may be obtained using the following functions:
Point
• [991]
X(p)
Returns the X-coordinate value for the
mysql> SELECT X(POINT(56.7, 53.34));
+-----------------------+
| X(POINT(56.7, 53.34)) |
+-----------------------+
|
Spatial Analysis Functions
[991]
[991]
[991]
[991]
EMPTY
[991]
Hierarchy".)
56.7 |
Geometry
|
101 |
values such as
POINT
object as a double-precision number.
Point p
991
|
subclasses.
EMPTY.
Section 12.16.2.1,
is a
g