Kategorien:: Geodatenfunktionen

ST_COVERS¶

This returns TRUE if no point in one geospatial object is outside of another geospatial object. In other words:

GEOGRAPHY object g2 is outside GEOGRAPHY object g1.
GEOMETRY object g2 is outside GEOMETRY object g1.

ST_COVERS ist ähnlich, unterscheidet sich aber geringfügig von ST_CONTAINS. Weitere Details zu den Unterschieden zwischen „deckt ab“ und „enthält“ finden Sie unter DE-9IM (Dimensionally Extended 9-Intersection Model).

Although ST_COVERS and ST_CONTAINS might seem similar, the two functions have subtle differences. For details on the differences between „covers“ and „contains“, see the Dimensionally Extended 9-Intersection Model (DE-9IM).

Bemerkung

Diese Funktion unterstützt nicht die Verwendung einer GeometryCollection oder FeatureCollection als Eingabewert.

Siehe auch:: ST_CONTAINS , ST_COVEREDBY

Syntax¶

ST_COVERS( <geography_expression_1> , <geography_expression_2> )

ST_COVERS( <geometry_expression_1> , <geometry_expression_2> )

Argumente¶

geography_expression_1: Ein GEOGRAPHY-Objekt, das nicht ein GeometryCollection oder FeatureCollection ist.
geography_expression_2: Ein GEOGRAPHY-Objekt, das nicht ein GeometryCollection oder FeatureCollection ist.
geometry_expression_1: A GEOMETRY object that is not a GeometryCollection or FeatureCollection.
geometry_expression_2: A GEOMETRY object that is not a GeometryCollection or FeatureCollection.

Rückgabewerte¶

Ein BOOLEAN-Wert.

Usage Notes¶

For GEOMETRY objects, the function reports an error if the two input GEOMETRY objects have different SRIDs.

Beispiele¶

GEOGRAPHY Examples¶

Das folgende Beispiel zeigt eine einfache Verwendung der Funktion ST_COVERS:

create table geospatial_table_01 (g1 GEOGRAPHY, g2 GEOGRAPHY);
insert into geospatial_table_01 (g1, g2) values 
    ('POLYGON((0 0, 3 0, 3 3, 0 3, 0 0))', 'POLYGON((1 1, 2 1, 2 2, 1 2, 1 1))');

SELECT ST_COVERS(g1, g2) 
    FROM geospatial_table_01;
+-------------------+
| ST_COVERS(G1, G2) |
|-------------------|
| True              |
+-------------------+

GEOMETRY Examples¶

The query below shows several examples of using ST_COVERS. Note how the Polygon covers (but does not contain) a LineString on its border.

SELECT ST_COVERS(poly, poly_inside),
       ST_COVERS(poly, poly),
       ST_COVERS(poly, line_on_boundary),
       ST_COVERS(poly, line_inside)
  FROM (SELECT TO_GEOMETRY('POLYGON((-2 0, 0 2, 2 0, -2 0))') AS poly,
               TO_GEOMETRY('POLYGON((-1 0, 0 1, 1 0, -1 0))') AS poly_inside,
               TO_GEOMETRY('LINESTRING(-1 1, 0 2, 1 1)') AS line_on_boundary,
               TO_GEOMETRY('LINESTRING(-2 0, 0 0, 0 1)') AS line_inside);

+------------------------------+----------------------+----------------------------------+-----------------------------+
| ST_COVERS(POLY, POLY_INSIDE) | ST_COVERS(POLY,POLY) | ST_COVERS(POLY,LINE_ON_BOUNDARY) | ST_COVERS(POLY,LINE_INSIDE) |
|------------------------------+----------------------+----------------------------------+-----------------------------|
| True                         | True                 | True                             | True                        |
+------------------------------+----------------------+----------------------------------+-----------------------------+