ST_AREA (NoSQL query)
APPLIES TO: NoSQL
Returns the total area of a GeoJSON Polygon or MultiPolygon expression.
Note
For more information, see Geospatial and GeoJSON location data.
Syntax
ST_AREA(<spatial_expr>)
Arguments
Description | |
---|---|
spatial_expr |
Any valid GeoJSON Polygon or MultiPolygon expression. |
Return types
Returns a numeric expression that enumerates the total area of a set of points.
Examples
The following example shows how to return the area of a polygon.
SELECT VALUE {
areaPolygon: ST_AREA({
"type": "Polygon",
"coordinates": [ [
[ 31.8, -5 ],
[ 32, -5 ],
[ 32, -4.7 ],
[ 31.8, -4.7 ],
[ 31.8, -5 ]
] ]
})
}
[
{
"areaPolygon": 735970283.0522614
}
]
Remarks
- The result is expressed in square meters for the default reference system.
- Using this function to calculate the area of zero or one-dimensional figures like GeoJSON Points and LineStrings results in an area of
0
. - The GeoJSON specification requires that points within a Polygon be specified in counter-clockwise order. A Polygon specified in clockwise order represents the inverse of the region within it.