카테고리:: 지리 공간 함수

ST_AREA¶

Returns the area of the Polygon(s) in a GEOGRAPHY or GEOMETRY object.

구문¶

ST_AREA( <geography_or_geometry_expression> )

인자¶

geography_expression: The argument must be of type GEOGRAPHY or GEOMETRY.

반환¶

Returns a REAL value, which represents the area:

For GEOGRAPHY input values, the area is in square meters.
For GEOMETRY input values, the area is computed with the same units used to define the input coordinates.

사용법 노트¶

geography_expression 이 Polygon, MultiPolygon, 또는 다각형을 포함하는 GeometryCollection이 아닌 경우, ST_AREA는 0을 반환합니다.
geography_expression 이 GeometryCollection인 경우, ST_AREA는 컬렉션에 있는 다각형 영역의 합계를 반환합니다.

예¶

GEOGRAPHY Examples¶

This uses the ST_AREA function with GEOGRAPHY objects to calculate the area of Earth’s surface 1 degree on each side with the bottom of the area on the equator:

SELECT ST_AREA(TO_GEOGRAPHY('POLYGON((0 0, 1 0, 1 1, 0 1, 0 0))')) AS area;
+------------------+
|             AREA |
|------------------|
| 12364036567.0764 |
+------------------+

GEOMETRY Examples¶

The following example calls the ST_AREA function with GEOMETRY objects that represent a Point, LineString, and Polygon.

SELECT ST_AREA(g), ST_ASWKT(g)
FROM (SELECT TO_GEOMETRY(column1) as g
  from values ('POINT(1 1)'),
              ('LINESTRING(0 0, 1 1)'),
              ('POLYGON((0 0, 0 1, 1 1, 1 0, 0 0))'));

+------------+--------------------------------+
| ST_AREA(G) | ST_ASWKT(G)                    |
|------------+--------------------------------|
|          0 | POINT(1 1)                     |
|          0 | LINESTRING(0 0,1 1)            |
|          1 | POLYGON((0 0,0 1,1 1,1 0,0 0)) |
+------------+--------------------------------+