STV_Extent

Returns a bounding box containing all of the input data.

Use STV_Extent inside of a nested query for best results. The OVER clause must be empty.

Important

STV_Extent does not return a valid polygon when the input is a single point.

Behavior type

Syntax

STV_Extent( g )

Arguments

g: Spatial object, type GEOMETRY.

Returns

GEOMETRY

Supported data types

Data Type	GEOMETRY
Point	Yes
Multipoint	Yes
Linestring	Yes
Multilinestring	Yes
Polygon	Yes
Multipolygon	Yes
GeometryCollection	Yes

Examples

The following examples show how you can use STV_Extent.

Return the bounding box of a linestring, and verify that it is a valid polygon:

=> SELECT ST_AsText(geom) AS bounding_box, ST_IsValid(geom)
   FROM (SELECT STV_Extent(ST_GeomFromText('LineString(0 0, 1 1)')) OVER() AS geom) AS g;
            bounding_box             | ST_IsValid
-------------------------------------+------------
 POLYGON ((0 0, 1 0, 1 1, 0 1, 0 0)) | t
(1 row)

Return the bounding box of spatial objects in a table:

=> CREATE TABLE misc_geo_shapes (id IDENTITY, geom GEOMETRY);
CREATE TABLE
=> COPY misc_geo_shapes (gx FILLER LONG VARCHAR, geom AS ST_GeomFromText(gx)) FROM STDIN;
Enter data to be copied followed by a newline.
End with a backslash and a period on a line by itself.
>> POINT(-71.03 42.37)
>> LINESTRING(-71.058849 42.367501, -71.062240 42.371276, -71.067938 42.371246)
>> POLYGON((-71.066030 42.380617, -71.055827 42.376734, -71.060811 42.376011, -71.066030 42.380617))
>> \.
=> SELECT ST_AsText(geom_col) AS bounding_box
   FROM (SELECT STV_Extent(geom) OVER() AS geom_col FROM misc_geo_shapes) AS g;
                                                   bounding_box
------------------------------------------------------------------------------------------------------------------
 POLYGON ((-71.067938 42.367501, -71.03 42.367501, -71.03 42.380617, -71.067938 42.380617, -71.067938 42.367501))
(1 row)