Oracle 5.0 Reference Manual page 1016

•
GeometryN(gc,N)
12.16.5.3.2. Spatial Operators
OpenGIS proposes a number of other functions that can produce geometries. They are designed to
implement spatial operators.
These functions are not implemented in MySQL.
•
Buffer(g,d)
Returns a geometry that represents all points whose distance from the geometry value
or equal to a distance of d.
•
ConvexHull(g)
Returns a geometry that represents the convex hull of the geometry value g.
•
Difference(g1,g2)
Returns a geometry that represents the point set difference of the geometry value
•
Intersection(g1,g2)
Returns a geometry that represents the point set intersection of the geometry values
•
SymDifference(g1,g2)
Returns a geometry that represents the point set symmetric difference of the geometry value
g2.
•
Union(g1,g2)
Returns a geometry that represents the point set union of the geometry values
12.16.5.4. Functions for Testing Spatial Relations Between Geometric Objects
The functions described in these sections take two geometries as input parameters and return a
qualitative or quantitative relation between them.
12.16.5.4.1. Relations on Geometry Minimal Bounding Rectangles (MBRs)
MySQL provides several functions that test relations between minimal bounding rectangles of two
geometries
•
MBRContains(g1,g2)
Returns 1 or 0 to indicate whether the Minimum Bounding Rectangle of
Bounding Rectangle of g2. This tests the opposite relationship as
mysql> SET @g1 = GeomFromText('Polygon((0 0,0 3,3 3,3 0,0 0))');
mysql> SET @g2 = GeomFromText('Point(1 1)');
mysql> SELECT MBRContains(@g1,@g2), MBRContains(@g2,@g1);
----------------------+----------------------+
| MBRContains(@g1,@g2) | MBRContains(@g2,@g1) |
+----------------------+----------------------+
|
+----------------------+----------------------+
•
MBRDisjoint(g1,g2)
Returns 1 or 0 to indicate whether the Minimum Bounding Rectangles of the two geometries
are disjoint (do not intersect).
g2
Spatial Analysis Functions
[995]
[996]
[996]
[996]
[996]
[996]
[996]
and g2. The return values 1 and 0 indicate true and false, respectively.
g1
[996]
1 |
[996]
0 |
996
g
with g2.
g1
with g2.
g1
and g2.
g1
contains the Minimum
g1
[997].
MBRWithin()
is less than
with
g1
and
g1