名称
ST_Touches — 测试两个几何图形是否至少有一个共同点，但它们的内部不相交
大纲
boolean ST_Touches(geometry A, geometry B);
描述
如果 A 和 B 相交，但它们的内部不相交，则返回 TRUE。 等价地，A和B至少有一个公共点，并且公共点至少位于一个边界内。 对于点/点输入，关系始终为 FALSE，因为点没有边界。
在数学术语中：ST_Touches(A, B) ⇔ (Int(A) ⋂ Int(B) = ∅) ∧ (A ⋂ B ≠ ∅)
如果两个几何图形的 DE-9IM 交集矩阵匹配以下之一，则此关系成立：
-
FT*******
-
F**T*****
-
F***T****
![[注意]](../images/note.png)
|
|
|
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，请改用 |
增强：3.0.0 启用了对 GEOMETRYCOLLECTION 的支持
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: 5.1.28
示例
ST_Touches 谓词在以下示例中返回 TRUE。
Two Polygons touching along a boundary segment.
SELECT ST_Touches(a, b) FROM (SELECT 'POLYGON ((10 190,10 70,80 70,80 130,50 160,120 160,120 190,10 190))'::geometry AS a, 'POLYGON ((80 110,140 140,190 110,180 40,140 10,80 50,80 70,80 110))'::geometry AS b ) AS example;
t
Two Polygons touching at a boundary point.
SELECT ST_Touches(a, b) FROM (SELECT 'POLYGON ((10 190,10 70,80 70,80 130,50 160,120 160,120 190,10 190))'::geometry AS a, 'POLYGON ((140 140,190 110,180 40,140 10,80 70,140 140))'::geometry AS b ) AS example;
t
A Polygon and a LineString touching at the line endpoint.
SELECT ST_Touches(a, b) FROM (SELECT 'POLYGON ((80 10,50 40,50 90,80 130,140 120,160 70,140 30,80 10))'::geometry AS a, 'LINESTRING (30 190,180 150,160 70)'::geometry AS b ) AS example;
t
Two LineStrings touching at their endpoints.
SELECT ST_Touches(a, b) FROM (SELECT 'LINESTRING (10 10,60 140,140 190)'::geometry AS a, 'LINESTRING (140 190,190 10)'::geometry AS b ) AS example;
t
Two LineStrings touching where an endpoint meets the other line.
SELECT ST_Touches(a, b) FROM (SELECT 'LINESTRING (10 10,60 140,140 190)'::geometry AS a, 'LINESTRING (60 140,190 10)'::geometry AS b ) AS example;
t
A Point touching a Polygon boundary.
SELECT ST_Touches(a, b) FROM (SELECT 'POLYGON ((30 30,10 110,40 190,120 170,180 180,170 100,130 10,30 30))'::geometry AS a, 'POINT (170 100)'::geometry AS b ) AS example;
t
SELECT ST_Touches('LINESTRING(0 0,1 1,0 2)'::geometry, 'POINT(1 1)'::geometry);
f
SELECT ST_Touches('LINESTRING(0 0,1 1,0 2)'::geometry, 'POINT(0 2)'::geometry);
t