Additional Resources These standards are important for the MySQL implementation of spatial operations: If you have questions or concerns about the use of the spatial extensions to MySQL, you can discuss them in the GIS forum: https://forums.mysql.com/list.php?23. MySQL has spatial data types that correspond to OpenGIS classes. The basis for these types is described in Section 11.4.2, “The OpenGIS Geometry Model” . Some spatial data types hold single geometry values: GEOMETRY  can store geometry values of any type. The other single-value types ( POINT ,  LINESTRING , and  POLYGON ) restrict their values to a particular geometry type. The other spatial data types hold collections of values: GEOMETRYCOLLECTION  can store a collection of objects of any type. The other collection types ( MULTIPOINT ,  MULTILINESTRING , and  MULTIPOLYGON ) restrict collection members to those having a particular geometry type. Example: To create a table named  geom  that has a column named  g  that can store values of any geometry type, use this statement: • MULTIPOINT • MULTILINESTRING • MULTIPOLYGON • GEOMETRYCOLLECTION • GEOMETRY • POINT • LINESTRING • POLYGON •The grammar for spatial reference system (SRS) definitions is based on the grammar defined in OpenGIS Implementation Specification: Coordinate Transformation Services , Revision 1.00, OGC 01-009, January 12, 2001, Section 7.2. This specification is available at http://www.opengeospatial.org/ standards/ct. For differences from that specification in SRS definitions as implemented in MySQL, see Section 13.1.19, “CREATE SPATIAL REFERENCE SYSTEM Statement” . •The Open Geospatial Consortium publishes the  OpenGISfi Implementation Standard for Geographic information , a document that proposes several conceptual ways for extending an SQL RDBMS to support spatial data. See in particular Simple Feature Access - Part 1: Common Architecture, and Simple Feature Access - Part 2: SQL Option. The Open Geospatial Consortium (OGC) maintains a website at http://www.opengeospatial.org/. The specification is available there at http:// www.opengeospatial.org/standards/sfs. It contains additional information relevant to the material here. •SQL/MM Part 3: Spatial. Additional Resources 11.4.1 Spatial Data Types 2050