ST_AREA

描述

计算地球球面上区域的面积

语法

ST_Area_Square_Meters( <geo>)
ST_Area_Square_Km( <geo>)

参数

参数	说明
<geo>	地球球面位置

返回值

ST_Area_Square_Meters( ) 返回的单位是平方米

ST_Area_Square_Km( ) 返回的单位是平方千米。

举例

SELECT ST_Area_Square_Meters(ST_Circle(0, 0, 1));

+-------------------------------------------------+
| st_area_square_meters(st_circle(0.0, 0.0, 1.0)) |
+-------------------------------------------------+
|                              3.1415926535897869 |
+-------------------------------------------------+

SELECT ST_Area_Square_Km(ST_Polygon("POLYGON ((0 0, 1 0, 1 1, 0 1, 0 0))"));

+----------------------------------------------------------------------+
| st_area_square_km(st_polygon('POLYGON ((0 0, 1 0, 1 1, 0 1, 0 0))')) |
+----------------------------------------------------------------------+
|                                                   12364.036567076409 |
+----------------------------------------------------------------------+

SELECT ST_Area_Square_Meters(ST_Point(0, 1));

+-------------------------------------------+
| st_area_square_meters(st_point(0.0, 1.0)) |
+-------------------------------------------+
|                                         0 |
+-------------------------------------------+

SELECT ST_Area_Square_Meters(ST_LineFromText("LINESTRING (1 1, 2 2)"));

+-----------------------------------------------------------------+
| st_area_square_meters(st_linefromtext('LINESTRING (1 1, 2 2)')) |
+-----------------------------------------------------------------+
|                                                               0 |
+-----------------------------------------------------------------+