13.1.19 CREATE SPATIAL REFERENCE SYSTEM Syntax

This statement creates a spatial reference system (SRS) definition and stores it in the data dictionary. The definition can be inspected using the INFORMATION_SCHEMA ST_SPATIAL_REFERENCE_SYSTEMS table. This statement requires the SUPER privilege.

If neither OR REPLACE nor IF NOT EXISTS is specified, an error occurs if an SRS definition with the SRID value already exists.

With CREATE OR REPLACE syntax, any existing SRS definition with the same SRID value is replaced, unless the SRID value is used by some column in an existing table. In that case, an error occurs. For example:

To identify which column or columns use the SRID, use this query:

With CREATE ... IF NOT EXISTS syntax, any existing SRS definition with the same SRID value causes the new definition to be ignored and a warning occurs.

SRID values must be in the range of 32-bit unsigned integers, with these restrictions:

Attributes for the statement must satisfy these conditions:

Here is an example CREATE SPATIAL REFERENCE SYSTEM statement. The DEFINITION value is reformatted across multiple lines for readability. (For the statement to be legal, the value actually must be given on a single line.)

The grammar for 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.

MySQL incorporates these changes to the specification:

If an SRS definition specifies an authority code for the projection (which is recommended), an error occurs if the definition is missing mandatory parameters. In this case, the error message indicates what the problem is. The projection methods and mandatory parameters that MySQL supports are shown in Table 13.7, “Supported Spatial Reference System Projection Methods” and Table 13.8, “Spatial Reference System Projection Parameters”.

For additional information about writing SRS definitions for MySQL, see Geographic Spatial Reference Systems in MySQL 8.0 and Projected Spatial Reference Systems in MySQL 8.0

The following table shows the projection methods that MySQL supports. MySQL permits unknown projection methods but cannot check the defintion for mandatory paramters and cannot convert spatial data to or from an unknown projection. For detailed explanations of how each projection works, including formulas, see EPSG Guidance Note 7-2.

The following table shows the projection parameters that MySQL recognizes. Recognition occurs primarily by authority code. If there is no authority code, MySQL falls back to case-insensitive string matching on the parameter name. For details about each parameter, look it up by code in the EPSG Online Registry.