描述

返回点的Y坐标，如果不可用，则返回值为空。输入必须是一个点。

This method implements the OGC Simple Features Implementation Specification for SQL 1.1.

This method implements the SQL/MM specification. SQL-MM 3：6.1.4

This function supports 3d and will not drop the z-index.

示例

SELECT ST_Y(ST_GeomFromEWKT('POINT(1 2 3 4)'));
 st_y
------
        2
(1 row)

SELECT ST_Y(ST_Centroid(ST_GeomFromEWKT('LINESTRING(1 2 3 4, 1 1 1 1)')));
 st_y
------
  1.5
(1 row)


                

另请参阅

ST_Centroid , ST_GeomFromEWKT , ST_M , ST_X , ST_YMax , ST_YMin , ST_Z