ST_Area_Square_Meters,ST_Area_Square_Km

Syntax

1. DOUBLE ST_Area_Square_Meters(GEOMETRY geo)
2. DOUBLE ST_Area_Square_Km(GEOMETRY geo)

description

计算地球球面上区域的面积，目前参数geo支持St_Point,St_LineString,St_Circle和St_Polygon。

如果输入的是St_Point,St_LineString，则返回零。

其中，ST_Area_Square_Meters(GEOMETRY geo)返回的单位是平方米，ST_Area_Square_Km(GEOMETRY geo)返回的单位是平方千米。

example

1. mysql> SELECT ST_Area_Square_Meters(ST_Circle(0, 0, 1));
2. +-------------------------------------------------+
3. | st_area_square_meters(st_circle(0.0, 0.0, 1.0)) |
4. +-------------------------------------------------+
5. |                              3.1415926535897869 |
6. +-------------------------------------------------+
7. 1 row in set (0.04 sec)

9. mysql> SELECT ST_Area_Square_Km(ST_Polygon("POLYGON ((0 0, 1 0, 1 1, 0 1, 0 0))"));
10. +----------------------------------------------------------------------+
11. | st_area_square_km(st_polygon('POLYGON ((0 0, 1 0, 1 1, 0 1, 0 0))')) |
12. +----------------------------------------------------------------------+
13. |                                                   12364.036567076409 |
14. +----------------------------------------------------------------------+
15. 1 row in set (0.01 sec)

17. mysql> SELECT ST_Area_Square_Meters(ST_Point(0, 1));
18. +-------------------------------------------+
19. | st_area_square_meters(st_point(0.0, 1.0)) |
20. +-------------------------------------------+
21. |                                         0 |
22. +-------------------------------------------+
23. 1 row in set (0.05 sec)

25. mysql> SELECT ST_Area_Square_Meters(ST_LineFromText("LINESTRING (1 1, 2 2)"));
26. +-----------------------------------------------------------------+
27. | st_area_square_meters(st_linefromtext('LINESTRING (1 1, 2 2)')) |
28. +-----------------------------------------------------------------+
29. |                                                               0 |
30. +-----------------------------------------------------------------+
31. 1 row in set (0.03 sec)

keywords

ST_Area_Square_Meters,ST_Area_Square_Km,ST_Area,ST,Area