描述

给定的两个行字符串返回一个介于-3和3之间的整数，指示它们之间存在哪种交叉行为。0表示无交叉。仅在以下情况下才支持 LINESTRING s.

交叉号的含义如下：

可用性：1.4

示例

示例： 左交叉直线和右交叉直线

蓝色：A行；绿色：B行

SELECT ST_LineCrossingDirection(lineA, lineB) As A_cross_B,
       ST_LineCrossingDirection(lineB, lineA) As B_cross_A
FROM (SELECT
  ST_GeomFromText('LINESTRING(25 169,89 114,40 70,86 43)') As lineA,
  ST_GeomFromText('LINESTRING (20 140, 71 74, 161 53)') As lineB
  ) As foo;

 A_cross_B | B_cross_A
-----------+-----------
        -1 |         1

示例： 行多点结束相同的第一个左侧和行多点结束相同的第一个右

蓝色：A行；绿色：B行

SELECT ST_LineCrossingDirection(lineA, lineB) As A_cross_B,
       ST_LineCrossingDirection(lineB, lineA) As B_cross_A
FROM (SELECT
 ST_GeomFromText('LINESTRING(25 169,89 114,40 70,86 43)') As lineA,
 ST_GeomFromText('LINESTRING(171 154,20 140,71 74,161 53)') As lineB
  ) As foo;

 A_cross_B | B_cross_A
-----------+-----------
         3 |        -3

示例： 线多点左端和线多点右端

蓝色：A行；绿色：B行

SELECT ST_LineCrossingDirection(lineA, lineB) As A_cross_B,
       ST_LineCrossingDirection(lineB, lineA) As B_cross_A
FROM (SELECT
  ST_GeomFromText('LINESTRING(25 169,89 114,40 70,86 43)') As lineA,
  ST_GeomFromText('LINESTRING(5 90, 71 74, 20 140, 171 154)') As lineB
  ) As foo;

 A_cross_B | B_cross_A
-----------+-----------
        -2 |         2

示例： 线多点左端和线多点右端

蓝色：A行；绿色：B行

SELECT ST_LineCrossingDirection(lineA, lineB) As A_cross_B,
       ST_LineCrossingDirection(lineB, lineA) As B_cross_A
FROM (SELECT
  ST_GeomFromText('LINESTRING(25 169,89 114,40 70,86 43)') As lineA,
  ST_GeomFromText('LINESTRING (171 154, 20 140, 71 74, 2.99 90.16)') As lineB
) As foo;

 A_cross_B | B_cross_A
-----------+-----------
         2 |        -2

SELECT s1.gid, s2.gid, ST_LineCrossingDirection(s1.geom, s2.geom)
  FROM streets s1 CROSS JOIN streets s2
         ON (s1.gid != s2.gid AND s1.geom && s2.geom )
WHERE ST_LineCrossingDirection(s1.geom, s2.geom) > 0;

另请参阅

ST_Crosses