Catégories :: Fonctions géospatiales

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 est similaire, mais subtilement différent de ST_CONTAINS. Pour plus de détails sur les différences entre « covers » (couvre) et « contains » (contient), voir le modèle à 9 intersections dimensionnellement étendu (DE-9IM).

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).

Note

Cette fonction ne prend pas en charge l’utilisation de GeometryCollection ou de FeatureCollection comme valeurs d’entrée.

Voir aussi :: ST_CONTAINS , ST_COVEREDBY

Syntaxe¶

ST_COVERS( <geography_expression_1> , <geography_expression_2> )

ST_COVERS( <geometry_expression_1> , <geometry_expression_2> )

Arguments¶

geography_expression_1: Un objet GEOGRAPHY qui n’est pas un GeometryCollection ou un FeatureCollection.
geography_expression_2: Un objet GEOGRAPHY qui n’est pas un GeometryCollection ou un FeatureCollection.
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.

Renvoie¶

BOOLEAN.

Usage Notes¶

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

Exemples¶

GEOGRAPHY Examples¶

Cela montre une utilisation simple de la fonction 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                        |
+------------------------------+----------------------+----------------------------------+-----------------------------+