Data-Analysis: Well-known text (WKT)

Mon, 01 Jan 0001 00:00:00 +0000

Well-Known Text (WKT) is an ASCII representation of a spatial object.

WKTs are not case sensitive; the database recognizes any combination of lowercase and uppercase letters.

Some examples of valid WKTs are:

WKT Example	Description
POINT(1 2)	The point (1,2)
MULTIPOINT(0 0,1 1)	A set made up of the points (0,0) and (1,1)
LINESTRING(1.5 2.45,3.21 4)	The line from the point (1.5,2.45) to the point (3.21,4)
MULTILINESTRING((0 0,–1 –2,–3 –4),(2 3,3 4,6 7))	Two linestrings, one that passes through (0,0), (–1,–2), and (–3,–4), and one that passes through (2,3), (3,4), and (6,7).
POLYGON((1 2,1 4,3 4,3 2,1 2))	The rectangle whose four corners are indicated by (1,2), (1,4), (3,4), and (3,2). A polygon must be closed, so the first and last points in the WKT must match.
POLYGON((0.5 0.5,5 0,5 5,0 5,0.5 0.5), (1.5 1,4 3,4 1,1.5 1))	A polygon (0.5 0.5,5 0,5 5,0 5,0.5 0.5) with a hole in it (1.5 1,4 3,4 1,1.5 1).
MULTIPOLYGON(((0 1,3 0,4 3,0 4,0 1)), ((3 4,6 3,5 5,3 4)), ((0 0,–1 –2,–3 –2,–2 –1,0 0)))	A set of three polygons
GEOMETRYCOLLECTION(POINT(5 8), LINESTRING(–1 3,1 4))	A set containing the point (5,8) and the line from (–1,3) to (1,4)
POINT EMPTY MULTIPOINT EMPTY LINESTRING EMPTY MULTILINESTRING EMPTY MULTILINESTRING(EMPTY) POLYGON EMPTY POLYGON(EMPTY) MULTIPOLYGON EMPTY MULTIPOLYGON(EMPTY)	Empty spatial objects; empty objects have no points.

Invalid WKTs are:

Data-Analysis: Well-known binary (WKB)

Mon, 01 Jan 0001 00:00:00 +0000

Well-Known Binary (WKB) is a binary representation of a spatial object. This format is primarily used to port spatial data between applications.