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

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

SELECT
    -- Bounding box over two points (ZIP + TRANSFORM)
    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()
;