ST_ISSIMPLE()

All functions > GEOSPATIAL > ST_ISSIMPLE()

Returns TRUE if a geometry has no anomalous geometric points such as self-intersections or self-tangencies.

Signatures

Is simple

Returns: TRUE if simple

ST_ISSIMPLE(geo: T) → BOOLEAN

With:

• T : Custom types: GEOM_POINT | GEOM_LINESTRING | GEOM_POLYGON | GEOM_MULTIPOINT | GEOM_MULTILINESTRING | GEOM_MULTIPOLYGON | GEOM_MULTIANY

Signature notes:

• A geometry is simple if it has no self-intersections except possibly at boundary points
• Points and MultiPoints are always simple unless two points are identical
• Polygons are simple if their rings do not self-intersect
• GEOMETRY only; not supported on BigQuery
• Returns NULL if the input is NULL

Examples

SELECT
    f1 := ST_ISSIMPLE(ST_GEOMFROMTEXT('LINESTRING (0 0, 1 1, 2 0)')), -- Simple line with no self-intersections
    f2 := ST_ISSIMPLE(ST_GEOMFROMTEXT('LINESTRING (0 0, 2 2, 2 0, 0 2)')) -- Figure-eight line: self-intersects at center
;