Name

ST_Overlaps — 测试两个几何图形是否具有相同的维度和相交,但每个几何图形至少有一个点不在另一个几何图形中

Synopsis

boolean ST_Overlaps(geometry A, geometry B);

描述

如果几何图形 A 和 B “空间重叠”,则返回 TRUE。 如果两个几何图形具有相同的维度,并且内部界面在同一维度中相交,并且至少有一个点在另一个点之外(相当于一个点没有覆盖另一个点),则称两个几何重叠。 重叠关系是对称且不自反的。

用数学术语来说: ST_Overlaps(A, B) ⇔ ( dim(A) = dim(B) = dim( Int(A) ⋂ Int(B) )) ∧ (A ⋂ B ≠ A) ∧ (A ⋂ B ≠ B )

[Note]

此功能自动包括利用几何上可用的任何空间索引的边界框比较。 要避免使用索引,请使用函数 _ST_Overlaps

它是通过GEOS模块实现的

[Important]

增强:3.0.0 启用了对 GEOMETRYCOLLECTION 的支持

注意:这是返回布尔值而不是整数的“允许”版本。

此方法实现了 SQL 1.1 的 OGC 简单功能规范。 s2.1.1.2 // s2.1.13.3

该方法实现了SQL/MM规范。 SQL-MM 3: 5.1.32

示例

ST_Overlaps在以下情况返回TRUE

MULTIPOINT / MULTIPOINT

LINESTRING / LINESTRING

POLYGON / POLYGON

包含 LineString 上的点,但由于它的维度较低,因此不会重叠或交叉。

SELECT ST_Overlaps(a,b) AS overlaps,       ST_Crosses(a,b) AS crosses,
       ST_Intersects(a, b) AS intersects,  ST_Contains(b,a) AS b_contains_a
FROM (SELECT ST_GeomFromText('POINT (100 100)') As a,
             ST_GeomFromText('LINESTRING (30 50, 40 160, 160 40, 180 160)')  AS b) AS t

overlaps | crosses | intersects | b_contains_a
---------+----------------------+--------------
f        | f       | t          | t

部分覆盖多边形的线串相交和交叉,但不重叠,因为它具有不同的维度。

SELECT ST_Overlaps(a,b) AS overlaps,        ST_Crosses(a,b) AS crosses,
       ST_Intersects(a, b) AS intersects,   ST_Contains(a,b) AS contains
FROM (SELECT ST_GeomFromText('POLYGON ((40 170, 90 30, 180 100, 40 170))') AS a,
             ST_GeomFromText('LINESTRING(10 10, 190 190)') AS b) AS t;

 overlap | crosses | intersects | contains
---------+---------+------------+--------------
 f       | t       | t          | f

两个多边形相交,但彼此都不包含对方,它们重叠,但不交叉,因为它们的交集具有相同的维度。

SELECT ST_Overlaps(a,b) AS overlaps,       ST_Crosses(a,b) AS crosses,
       ST_Intersects(a, b) AS intersects,  ST_Contains(b, a) AS b_contains_a,
       ST_Dimension(a) AS dim_a, ST_Dimension(b) AS dim_b,
       ST_Dimension(ST_Intersection(a,b)) AS dim_int
FROM (SELECT ST_GeomFromText('POLYGON ((40 170, 90 30, 180 100, 40 170))') AS a,
             ST_GeomFromText('POLYGON ((110 180, 20 60, 130 90, 110 180))') AS b) As t;

 overlaps | crosses | intersects | b_contains_a | dim_a | dim_b | dim_int
----------+---------+------------+--------------+-------+-------+-----------
 t        | f       | t          | f            |     2 |     2 |       2