ST_EXTENT()

All functions > GEOSPATIAL > ST_EXTENT()

Aggregate function that returns the bounding box of all geometries in a group as a polygon.

Signatures

Extent

Returns: Axis-aligned bounding rectangle enclosing all input geometries

ST_EXTENT(geo: T) → GEOM_POLYGON
sql
ParameterTypeRequiredDescription
geoTYesGeometry column to aggregate

With:

  • T : Custom types: GEOM_POINT | GEOM_LINESTRING | GEOM_POLYGON | GEOM_MULTIPOINT | GEOM_MULTILINESTRING | GEOM_MULTIPOLYGON | GEOM_MULTIANY

Signature notes:

  • Equivalent to ST_ENVELOPE(ST_UNION_AGG(geo)) but potentially more efficient
  • GEOMETRY only; for GEOGRAPHY use ST_CONVEXHULL(ST_UNION_AGG(geo)) instead
  • Not supported on BigQuery
  • NULL inputs are ignored
  • Returns NULL if all inputs are NULL

Examples

FeatureQL
SELECT
    f1 := ZIP(ARRAY[ST_GEOMPOINT(0.0, 0.0), ST_GEOMPOINT(3.0, 4.0)] AS geom).TRANSFORM(SELECT ST_ASTEXT(ST_EXTENT(geom))).UNWRAP_ONE() -- Bounding box over two points (ZIP + TRANSFORM)
;
Result
f1 VARCHAR
POLYGON ((0 0, 3 0, 3 4, 0 4, 0 0))

Last update at: 2026/05/26 17:22:09