ST_COVERS

Introduced or updated: v1.2.911

Returns TRUE if no point in the second GEOMETRY object lies outside the first GEOMETRY object.

See also: ST_COVEREDBY

Syntax

ST_COVERS(<geometry1>, <geometry2>)

Arguments

Arguments	Description
<geometry1>	A GEOMETRY expression (the covering object).
<geometry2>	A GEOMETRY expression (the object being tested).

Return Type

Boolean.

Examples

-- A polygon covers a smaller polygon inside it
SELECT ST_COVERS(
  TO_GEOMETRY('POLYGON((-2 0, 0 2, 2 0, -2 0))'),
  TO_GEOMETRY('POLYGON((-1 0, 0 1, 1 0, -1 0))')
);

┌────────┐
│ result │
├────────┤
│ true   │
└────────┘

-- A polygon covers a linestring on its boundary
SELECT ST_COVERS(
  TO_GEOMETRY('POLYGON((-2 0, 0 2, 2 0, -2 0))'),
  TO_GEOMETRY('LINESTRING(-1 1, 0 2, 1 1)')
);

┌────────┐
│ result │
├────────┤
│ true   │
└────────┘

-- A point outside the polygon is not covered
SELECT ST_COVERS(
  TO_GEOMETRY('POLYGON((0 0, 3 0, 3 3, 0 3, 0 0))'),
  TO_GEOMETRY('POINT(5 5)')
);

┌────────┐
│ result │
├────────┤
│ false  │
└────────┘