ST_IsRing
Determine whether a line geometry is a ring, that is, whether it is closed and simple.
Syntax
ST_IsRing(geo);- geo
- The input line geometry.
Type: ST_GEOMETRY(ANY)
Returns
A value of type BOOL that is TRUE if the line is a ring; otherwise FALSE.
Examples
SELECT inza..ST_IsRing(inza..ST_WKTToSQL('LINESTRING (0 0, 11 0, 11 11, 0 0))'));
ST_ISRING
---------
t
(1 row)SELECT inza..ST_IsRing(inza..ST_WKTToSQL('LINESTRING (1 2, 3 4, 5 6))'));
ST_ISRING
---------
f
(1 row)