12.18.3.1. Well-Known Text (WKT) Format

The Well-Known Text (WKT) representation of Geometry is designed to exchange geometry data in ASCII form. For a Backus-Naur grammar that specifies the formal production rules for writing WKT values, see the OpenGIS specification document referenced in Section 12.18, "Spatial Extensions".

Examples of WKT representations of geometry objects:

A Point:
```
POINT(15 20)
```
Note that point coordinates are specified with no separating comma. This differs from the syntax for the SQL POINT() function, which requires a comma between the coordinates. Take care to use the syntax appropriate to the context of a given spatial operation. For example, the following statements both extract the X-coordinate from a Point object. The first produces the object directly using the POINT() function. The second uses a WKT representation converted to a Point with GeomFromText().
```
mysql> SELECT X(POINT(15,
                    20));+------------------+| X(POINT(15, 20)) |+------------------+|               15 |+------------------+mysql> SELECT X(GeomFromText('POINT(15 20)'));+---------------------------------+| X(GeomFromText('POINT(15 20)')) |+---------------------------------+|                              15 |+---------------------------------+
```
A LineString with four points:
```
LINESTRING(0 0, 10 10, 20 25, 50 60)
```
Note that point coordinate pairs are separated by commas.
A Polygon with one exterior ring and one interior ring:
```
POLYGON((0 0,10 0,10 10,0 10,0 0),(5 5,7 5,7 7,5 7, 5 5))
```
A MultiPoint with three Point values:
```
MULTIPOINT(0 0, 20 20, 60 60)
```

A MultiLineString with two LineString values:

MULTILINESTRING((10 10, 20 20), (15 15, 30 15))

A MultiPolygon with two Polygon values:

MULTIPOLYGON(((0 0,10 0,10 10,0 10,0 0)),((5 5,7 5,7 7,5 7, 5 5)))

A GeometryCollection consisting of two Point values and one LineString:

GEOMETRYCOLLECTION(POINT(10 10), POINT(30 30), LINESTRING(15 15, 20 20))