ST_COLLECT

Collects multiple GEOMETRY values into a single GEOMETRY result.

This function supports GEOMETRY only.

Syntax

ST_COLLECT(<geometry>)

Arguments

Arguments	Description
<geometry>	An expression of type GEOMETRY.

Return Type

GEOMETRY. Depending on the input, the result can be a MULTIPOINT, MULTILINESTRING, MULTIPOLYGON, or GEOMETRYCOLLECTION.

note

• NULL input rows are ignored.
• If all input rows are NULL, the result is NULL.
• If the input GEOMETRY values use different SRIDs, the function returns an error.

Example

WITH data AS (
    SELECT TO_GEOMETRY('POINT(0 0)') AS g
    UNION ALL
    SELECT TO_GEOMETRY('LINESTRING(1 1,2 2)')
)
SELECT ST_ASWKT(ST_COLLECT(g)) FROM data;

╭────────────────────────────────────────────────────╮
│               st_aswkt(st_collect(g))              │
├────────────────────────────────────────────────────┤
│ GEOMETRYCOLLECTION(POINT(0 0),LINESTRING(1 1,2 2)) │
╰────────────────────────────────────────────────────╯