ST_Contains - CockroachDB

Given two shapes A and B, the predicate function ST_Contains(A, B) returns true if:

No point in B lies outside of shape A, and
At least one point in the interior of B lies in the interior of A.

In other words, the exterior of shape A must not include any point in B, and one or more points of B’s interior must lie in the interior of A. This behavior is similar to , except that the criteria are more exacting, and therefore some pairs of shapes will be rejected by this function that would be accepted by ST_Covers. ST_Contains works on the following data types:

“ will attempt to use any available to speed up its operation. Use the prefixed variant _ if you do not want any spatial indexes to be used.

This function is the inverse of .

Examples

The screenshots in these examples were generated using geojson.io, but they are designed to showcase the shapes, not the map. Representing GEOMETRY data in GeoJSON can lead to unexpected results if using geometries with other than 4326 (as shown below).

True

In this example, “ returns true because:

No point in the LineString B lies outside of the Polygon A, and
At least one point in the interior of B lies in the interior of A.

SELECT ST_Contains(st_geomfromtext('SRID=4326;POLYGON((-87.906471 43.038902, -95.992775 36.153980, -75.704722 36.076944, -87.906471 43.038902))'), st_geomfromtext('SRID=4326;LINESTRING(-88.243385 40.116421, -87.906471 43.038902, -95.992775 36.153980)'));

  st_contains
---------------
     true

(1 row)

False

In this example, “ returns false because:

At least one point in the interior of LineString B does not lie in the interior of the Polygon A.

Note that A query against these shapes with will return true.

SELECT st_contains(st_geomfromtext('SRID=4326;POLYGON((-87.906471 43.038902, -95.992775 36.153980, -75.704722 36.076944, -87.906471 43.038902))'), st_geomfromtext('SRID=4326;LINESTRING( -87.906471 43.038902, -95.992775 36.153980)'));

  st_contains
---------------
     false
(1 row)

​Examples

​True

​False

​See also

Examples

True

False

See also