- Catégories :
ST_YMAX¶
Returns the maximum latitude (Y coordinate) of all points contained in the specified GEOGRAPHY or GEOMETRY object.
Syntaxe¶
ST_YMAX( <geography_or_geometry_expression> )
Arguments¶
geography_or_geometry_expression
The argument must be an expression of type GEOGRAPHY or GEOMETRY.
Renvoie¶
Cela renvoie une valeur REAL.
Notes sur l’utilisation¶
La fonction tient compte de la courbure des bords vers les pôles.
Exemples¶
GEOGRAPHY Examples¶
Cela montre une utilisation simple des fonctions ST_XMIN, ST_XMAX, ST_YMIN et ST_YMAX :
CREATE or replace TABLE extreme_point_collection (id INTEGER, g GEOGRAPHY); INSERT INTO extreme_point_collection (id, g) SELECT column1, TO_GEOGRAPHY(column2) FROM VALUES (1, 'POINT(-180 0)'), (2, 'POINT(180 0)'), (3, 'LINESTRING(-179 0, 179 0)'), (4, 'LINESTRING(-60 30, 60 30)'), (5, 'LINESTRING(-60 -30, 60 -30)');SELECT g, ST_XMIN(g), ST_XMAX(g), ST_YMIN(g), ST_YMAX(g) FROM extreme_point_collection ORDER BY id; +----------------------------+------------+------------+-------------------+-------------------+ | G | ST_XMIN(G) | ST_XMAX(G) | ST_YMIN(G) | ST_YMAX(G) | |----------------------------+------------+------------+-------------------+-------------------| | POINT(-180 0) | -180 | 180 | 0 | 0 | | POINT(180 0) | -180 | 180 | 0 | 0 | | LINESTRING(-179 0,179 0) | -180 | 180 | -6.883275617e-14 | 6.883275617e-14 | | LINESTRING(-60 30,60 30) | -60 | 60 | 30 | 49.106605351 | | LINESTRING(-60 -30,60 -30) | -60 | 60 | -49.106605351 | -30 | +----------------------------+------------+------------+-------------------+-------------------+