ST_Disjoint

Determines if two GEOMETRY objects do not intersect or touch.

If ST_Disjoint returns TRUE for a pair of GEOMETRY objects, ST_Intersects returns FALSE for the same two objects.

GEOGRAPHY Polygons with a vertex or border on the International Date Line (IDL) or the North or South pole are not supported.

Behavior type

Immutable

Syntax

ST_Disjoint( g1, g2
                         [USING PARAMETERS spheroid={true | false}] )

Arguments

g1: Spatial object, type GEOMETRY
g2: Spatial object, type GEOMETRY

Parameters

spheroid = {true | false}

(Optional) BOOLEAN that specifies whether to use a perfect sphere or WGS84.

Default: False

Returns

BOOLEAN

Supported data types

Data Type	GEOMETRY	GEOGRAPHY (WGS84)
Point	Yes	Yes
Multipoint	Yes	No
Linestring	Yes	No
Multilinestring	Yes	No
Polygon	Yes	Yes
Multipolygon	Yes	No
GeometryCollection	Yes	No

Compatible GEOGRAPHY pairs:

Data Type: GEOGRAPHY (WGS84)
Point-Point: No
Linestring-Point: No
Polygon-Point: Yes
Multipolygon-Point: No

Examples

The following examples show how to use ST_Disjoint.

Two non-intersecting or touching polygons:

=> SELECT ST_Disjoint (ST_GeomFromText('POLYGON((-1 2,0 3,0 1,-1 2))'),
   ST_GeomFromText('POLYGON((1 0, 1 1, 2 2, 1 0))'));
 ST_Disjoint
-------------
 t
(1 row)

Two intersecting linestrings:

=> SELECT ST_Disjoint(ST_GeomFromText('LINESTRING(-1 2,0 3)'),
   ST_GeomFromText('LINESTRING(0 2,-1 3)'));
 ST_Disjoint
-------------
 f
(1 row)

Two polygons touching at a single point:

=> SELECT ST_Disjoint (ST_GeomFromText('POLYGON((-1 2, 0 3, 0 1, -1 2))'),
   ST_GeomFromText('POLYGON((0 2, 1 1, 1 2, 0 2))'));
 ST_Disjoint
--------------
 f
(1 row)