ST_UNION

Introduced or updated: v1.2.895

Returns the combined GEOMETRY made from two input GEOMETRY objects.

This function only supports GEOMETRY values.

Syntax

ST_UNION(<geometry1>, <geometry2>)

Arguments

Arguments	Description
<geometry1>	The argument must be an expression of type GEOMETRY.
<geometry2>	The argument must be an expression of type GEOMETRY.

note

• The function reports an error if the two input GEOMETRY objects have different SRIDs.

Return Type

GEOMETRY.

Examples

SELECT ST_ASWKT(ST_UNION(TO_GEOMETRY('POINT(0 0)'), TO_GEOMETRY('POINT(1 1)')));

╭──────────────────────────────────────────────────────────────────────────╮
│ st_aswkt(st_union(to_geometry('POINT(0 0)'), to_geometry('POINT(1 1)'))) │
├──────────────────────────────────────────────────────────────────────────┤
│ MULTIPOINT(0 0,1 1)                                                      │
╰──────────────────────────────────────────────────────────────────────────╯