描述

如果兩個幾何值之間的 3D 距離不超過距離 distance_of_srid，則返回 true。距離單位由幾何圖形的空間參考系統定義。為了使此函數有意義，源幾何圖形必須在同一坐標系統中（具有相同的 SRID）。

此函數支援 3D，並且不會捨棄 z 索引。

此函數支援多面體表面。

此方法實作 SQL/MM 規範。SQL-MM？

可用性：2.0.0

範例

-- Geometry example - units in meters (SRID: 2163 US National Atlas Equal area) (3D point and line compared 2D point and line)
-- Note: currently no vertical datum support so Z is not transformed and assumed to be same units as final.
SELECT ST_3DDWithin(
      ST_Transform(ST_GeomFromEWKT('SRID=4326;POINT(-72.1235 42.3521 4)'),2163),
      ST_Transform(ST_GeomFromEWKT('SRID=4326;LINESTRING(-72.1260 42.45 15, -72.123 42.1546 20)'),2163),
      126.8
    ) As within_dist_3d,
ST_DWithin(
      ST_Transform(ST_GeomFromEWKT('SRID=4326;POINT(-72.1235 42.3521 4)'),2163),
      ST_Transform(ST_GeomFromEWKT('SRID=4326;LINESTRING(-72.1260 42.45 15, -72.123 42.1546 20)'),2163),
      126.8
    ) As within_dist_2d;

 within_dist_3d | within_dist_2d
----------------+----------------
 f              | t

另請參閱

ST_3DDFullyWithin、ST_DWithin、ST_DFullyWithin、ST_3DDistance、ST_Distance、ST_3DMaxDistance、ST_Transform