PostGIS
Description
Returns true if the given geometries are "topologically equal". Use
this for a 'better' answer than '='. Topological equality means that the
geometries have the same dimension, and their point-sets occupy the same
space. This means that the order of vertices may be different in
topologically equal geometries. To verify the order of points is
consistent use ST_OrderingEquals (it must
be noted ST_OrderingEquals is a little more stringent than simply
verifying order of points are the same).
In mathematical terms: [.emphasis]#ST_Equals(A, B) ⇔ A = B #
The following relation holds: [.emphasis]#ST_Equals(A, B) ⇔ ST_Within(A,B) ∧ ST_Within(B,A) #
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[.inlinemediaobject]
This method implements the
OGC Simple Features
Implementation Specification for SQL 1.1.
s2.1.1.2
This
method implements the SQL/MM specification.
SQL-MM 3: 5.1.24
Changed: 2.2.0 Returns true even for invalid geometries if they are binary equal
Examples
SELECT ST_Equals(ST_GeomFromText('LINESTRING(0 0, 10 10)'),
ST_GeomFromText('LINESTRING(0 0, 5 5, 10 10)'));
st_equals
-----------
t
(1 row)
SELECT ST_Equals(ST_Reverse(ST_GeomFromText('LINESTRING(0 0, 10 10)')),
ST_GeomFromText('LINESTRING(0 0, 5 5, 10 10)'));
st_equals
-----------
t
(1 row)