ST_INTERSECTION_AGG

Aggregates multiple GEOMETRY values by repeatedly applying ST_INTERSECTION and returns the common overlapping part.

This function supports GEOMETRY only.

Syntax

ST_INTERSECTION_AGG(<geometry>)

Arguments

Arguments	Description
<geometry>	An expression of type GEOMETRY.

Return Type

GEOMETRY.

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('POLYGON((0 0,4 0,4 4,0 4,0 0))') AS g
    UNION ALL
    SELECT TO_GEOMETRY('POLYGON((1 1,3 1,3 3,1 3,1 1))')
)
SELECT ST_ASWKT(ST_INTERSECTION_AGG(g)) FROM data;

╭──────────────────────────────────╮
│ st_aswkt(st_intersection_agg(g)) │
├──────────────────────────────────┤
│ POLYGON((1 3,1 1,3 1,3 3,1 3))   │
╰──────────────────────────────────╯