16.5.1 Geometry Format Conversion Functions

16.5.1. Geometry Format Conversion Functions

MySQL supports the following functions for converting geometry values between internal format and either WKT or WKB format:

AsBinary(g)

Converts a value in internal geometry format to its WKB representation and returns the binary result.
```
SELECT AsBinary(g) FROM geom;
```

AsText(g)

Converts a value in internal geometry format to its WKT representation and returns the string result.

mysql> SET @g = 'LineString(1 1,2 2,3 3)';
mysql> SELECT AsText(GeomFromText(@g));
+--------------------------+
| AsText(GeomFromText(@g)) |
+--------------------------+
| LINESTRING(1 1,2 2,3 3)  |
+--------------------------+

GeomFromText(wkt[,srid])

Converts a string value from its WKT representation into internal geometry format and returns the result. A number of type-specific functions are also supported, such as PointFromText() and LineFromText(). See 項16.4.2.1. 「Creating Geometry Values Using WKT Functions」.
GeomFromWKB(wkb[,srid])

Converts a binary value from its WKB representation into internal geometry format and returns the result. A number of type-specific functions are also supported, such as PointFromWKB() and LineFromWKB(). See 項16.4.2.2. 「Creating Geometry Values Using WKB Functions」.