Documentation Home
MySQL 5.5 Reference Manual
Related Documentation Download this Manual Excerpts from this Manual

12.15.9.1 Spatial Relation Functions That Use Object Shapes

The OpenGIS specification defines the following functions. They test the relationship between two geometry values g1 and g2, using precise object shapes. The return values 1 and 0 indicate true and false, respectively.

  • Crosses(g1,g2)

    Returns 1 if g1 spatially crosses g2. Returns NULL if g1 is a Polygon or a MultiPolygon, or if g2 is a Point or a MultiPoint. Otherwise, returns 0.

    The term spatially crosses denotes a spatial relation between two given geometries that has the following properties:

    • The two geometries intersect

    • Their intersection results in a geometry that has a dimension that is one less than the maximum dimension of the two given geometries

    • Their intersection is not equal to either of the two given geometries

  • Touches(g1,g2)

    Returns 1 or 0 to indicate whether g1 spatially touches g2. Two geometries spatially touch if the interiors of the geometries do not intersect, but the boundary of one of the geometries intersects either the boundary or the interior of the other.


User Comments
Sign Up Login You must be logged in to post a comment.