geoDifference
Returns a new polygon with the difference of the second polygon clipped from the first polygon.
Syntax
geoDifference(polygon1, polygon2)
Parameters
Required. Polygon or MultiPolygon GeoJSON feature.
Required. Polygon or MultiPolygon GeoJSON feature to remove from polygon1.
Example
Return a GeoJSON Polygon that removes City Park (polygon2) from Colorado (polygon1).
SELECT geoDifference('{
"type": "Feature",
"properties": {
"name":"Colorado"
},
"geometry": {
"type": "Polygon",
"coordinates": [[
[-109.072265625,37.00255267215955],
[-102.01904296874999,37.00255267215955],
[-102.01904296874999,41.0130657870063],
[-109.072265625,41.0130657870063],
[-109.072265625,37.00255267215955]
]]
}
}',
'{
"type": "Feature",
"properties": {
"name":"City Park"
},
"geometry": {
"type": "Polygon",
"coordinates": [[
[-104.95973110198975,39.7543828214657],
[-104.95955944061278,39.744781185675386],
[-104.95904445648193,39.74422022399989],
[-104.95835781097412,39.74402223643582],
[-104.94097709655762,39.74392324244047],
[-104.9408483505249,39.75434982844515],
[-104.95973110198975,39.7543828214657]
]]
}
}'
)