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Polygon Functions
Area(poly)
Polygon value
poly, as measured in its spatial reference system.
mysql> SELECT Area(GeomFromText('Polygon((0 0,0 3,3 3,3 0,0 0),(1 1,1 2,2 2,2 1,1 1))'));
+----------------------------------------------------------------------------+
| Area(GeomFromText('Polygon((0 0,0 3,3 3,3 0,0 0),(1 1,1 2,2 2,2 1,1 1))')) |
+----------------------------------------------------------------------------+
| 8 |
+----------------------------------------------------------------------------+
|
NumInteriorRings(poly)
Polygon value poly.
mysql> SELECT NumInteriorRings(GeomFromText('Polygon((0 0,0 3,3 3,3 0,0 0),(1 1,1 2,2 2,2 1,1 1))'));
+----------------------------------------------------------------------------------------+
| NumInteriorRings(GeomFromText('Polygon((0 0,0 3,3 3,3 0,0 0),(1 1,1 2,2 2,2 1,1 1))')) |
+----------------------------------------------------------------------------------------+
| 1 |
+----------------------------------------------------------------------------------------+
|
ExteriorRing(poly)
Polygon value poly
as a LineString.
mysql> SELECT AsText(ExteriorRing(GeomFromText('Polygon((0 0,0 3,3 3,3 0,0 0),(1 1,1 2,2 2,2 1,1 1))')));
+--------------------------------------------------------------------------------------------+
| AsText(ExteriorRing(GeomFromText('Polygon((0 0,0 3,3 3,3 0,0 0),(1 1,1 2,2 2,2 1,1 1))'))) |
+--------------------------------------------------------------------------------------------+
| LINESTRING(0 0,0 3,3 3,3 0,0 0) |
+--------------------------------------------------------------------------------------------+
|
InteriorRingN(poly,n)
n-th interior ring for the Polygon value
poly as a LineString.
Ring numbers begin at 1.
mysql> SELECT AsText(InteriorRingN(GeomFromText('Polygon((0 0,0 3,3 3,3 0,0 0),(1 1,1 2,2 2,2 1,1 1))'),1));
+-----------------------------------------------------------------------------------------------+
| AsText(InteriorRingN(GeomFromText('Polygon((0 0,0 3,3 3,3 0,0 0),(1 1,1 2,2 2,2 1,1 1))'),1)) |
+-----------------------------------------------------------------------------------------------+
| LINESTRING(1 1,1 2,2 2,2 1,1 1) |
+-----------------------------------------------------------------------------------------------+
|