Function that checks
whether two geometries are identical
You can use the ST_Equals comparison function
to check whether
two geometries are identical.
ST_Equals
Use ST_Equals to determine if two geometries
are identical.
ST_Equals returns a value of 1 (one)
if two geometries are identical. The
order of the points used to define the geometries is not relevant
to the test
of equality. Figure 1. ST_Equals. The dark geometries represent geometry a; the gray geometries represent geometry b. In all cases, geometry a is equal to geometry b.
In the six examples (point, multipoint, linestring, multistring, polygon, and multipolygon) geometry a and geometry b are the same.
Table 1. Matrix
for equality. The DE-9IM pattern matrix
for equality ensures that the interiors intersect and that no part
interior
or boundary of either geometry intersects the exterior of the other.