UDF Relationships

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Relationship Tests

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ST_Contains

Overloads:

• ST_Contains(geometry1, geometry2) return true if geometry1 contains geometry2

Example:

SELECT ST_Contains(ST_Polygon(1,1, 1,4, 4,4, 4,1), ST_Point(2, 3)) from src LIMIT 1;  -- return true
SELECT ST_Contains(ST_Polygon(1,1, 1,4, 4,4, 4,1), ST_Point(8, 8)) from src LIMIT 1;  -- return false

ST_Crosses

Overloads:

• ST_Crosses(geometry1, geometry2) return true if geometry1 crosses geometry2

Example:

SELECT ST_Crosses(st_linestring(0,0, 1,1), st_linestring(1,0, 0,1)) from src LIMIT 1;  -- return true
SELECT ST_Crosses(st_linestring(2,0, 2,3), st_polygon(1,1, 1,4, 4,4, 4,1)) from src LIMIT 1;  -- return true
SELECT ST_Crosses(st_linestring(0,2, 0,1), ST_linestring(2,0, 1,0)) from src LIMIT 1;  -- return false

ST_Disjoint

Overloads:

• ST_Disjoint(geometry1, geometry2) return true if the intersection of geometry1 and geometry2 is empty

Example:

SELECT ST_Disjoint(ST_LineString(0,0, 0,1), ST_LineString(1,1, 1,0)) from src LIMIT 1;  -- return true
SELECT ST_Disjoint(ST_LineString(0,0, 1,1), ST_LineString(1,0, 0,1)) from src LIMIT 1;  -- return false

ST_EnvIntersects

Overloads:

• ST_EnvIntersects(ST_Geometry1, ST_Geometry2) return true if the envelopes of ST_Geometry1 and ST_Geometry2 intersect

Example:

SELECT ST_EnvIntersects(ST_LineString(0,0, 1,1), ST_LineString(1,3, 2,2)) from src LIMIT 1;  -- return false
SELECT ST_EnvIntersects(ST_LineString(0,0, 2,2), ST_LineString(1,0, 3,2)) from src LIMIT 1;  -- return true

ST_Equals

Overloads:

• ST_Equals(geometry1, geometry2) return true if geometry1 equals geometry2

Example:

SELECT ST_Equals(st_linestring(0,0, 1,1), st_linestring(1,1, 0,0)) from src LIMIT 1;  -- return true
SELECT ST_Equals(st_linestring(0,0, 1,1), st_linestring(1,0, 0,1)) from src LIMIT 1;  -- return false

ST_Intersects

Overloads:

• ST_Intersects(geometry1, geometry2) return true if geometry1 intersects geometry2

Example:

SELECT ST_Intersects(st_linestring(0,0, 1,1), st_linestring(1,1, 0,0)) from src LIMIT 1;  -- return true
SELECT ST_Intersects(st_linestring(0,0, 1,1), st_linestring(1,0, 0,1)) from src LIMIT 1;  -- return true
SELECT ST_Intersects(ST_LineString(2,0, 2,3), ST_Polygon(1,1, 4,1, 4,4, 1,4)) from src LIMIT 1;  -- return true
SELECT ST_Intersects(ST_LineString(8,7, 7,8), ST_Polygon(1,1, 4,1, 4,4, 1,4)) from src LIMIT 1;  -- return false

ST_Overlaps

Overloads:

• ST_Overlaps(geometry1, geometry2) return true if geometry1 overlaps geometry2

Example:

SELECT ST_Overlaps(st_polygon(2,0, 2,3, 3,0), st_polygon(1,1, 1,4, 4,4, 4,1)) from src LIMIT 1;  -- return true
SELECT ST_Overlaps(st_polygon(2,0, 2,1, 3,1), ST_Polygon(1,1, 1,4, 4,4, 4,1)) from src LIMIT 1;  -- return false

ST_Relate

Overloads:

• ST_Relate(geometry1, geometry2) return true if geometry1 has the specified DE-9IM relationship with geometry2

Example:

SELECT ST_Relate(st_polygon(2,0, 2,1, 3,1), ST_Polygon(1,1, 1,4, 4,4, 4,1), '****T****') from src LIMIT 1;  -- true
SELECT ST_Relate(st_polygon(2,0, 2,1, 3,1), ST_Polygon(1,1, 1,4, 4,4, 4,1), 'T********') from src LIMIT 1;  -- false
SELECT ST_Relate(st_linestring(0,0, 3,3), ST_linestring(1,1, 4,4), 'T********') from src LIMIT 1;  -- true
SELECT ST_Relate(st_linestring(0,0, 3,3), ST_linestring(1,1, 4,4), '****T****') from src LIMIT 1;  -- false

ST_Touches

Overloads:

• ST_Touches(geometry1, geometry2) return true if geometry1 touches geometry2

Example:

SELECT ST_Touches(st_point(1, 2), st_polygon(1, 1, 1, 4, 4, 4, 4, 1)) from src LIMIT 1;  -- return true
SELECT ST_Touches(st_point(8, 8), st_polygon(1, 1, 1, 4, 4, 4, 4, 1)) from src LIMIT 1;  -- return false

ST_Within

Overloads:

• ST_Within(geometry1, geometry2) return true if geometry1 is within geometry2

Example:

SELECT ST_Within(st_point(2, 3), st_polygon(1,1, 1,4, 4,4, 4,1)) from src LIMIT 1;  -- return true
SELECT ST_Within(st_point(8, 8), st_polygon(1,1, 1,4, 4,4, 4,1)) from src LIMIT 1;  -- return false