Mysql-spatial-udf
MySQL Spatial User Defined Functions
MySQL Spatial User Defined Functions
This project add missing spatial functionality to MySQL through an UDF library. At this time this library implements more than 20 functions not present on current MySQL database.
What is an User Defined Function?
An User Defined Function (UDF) is a C/C++ library that extends the functionality of a MySQL server by adding new functions that behaves just like a native (built-in) MySQL functions like abs() or concat().
Build requirements
The code is written in C and requires the following libraries:
Building
on UNIX
On Linux or similars systems you will need to invoke the command "cmake ." This command will resolve dependences and generate an Makefile. After this a simple call to "make" will do the job.
on WINDOWS
If you have an MSVC 2010 compiler you can use included MySpatialUDF.sln project.
Before, you must correct the paths to search library dependences.
If you have another version of Visual Studio you will need to install cmake windows environment. cmake will build a Visual Studio Project with the version you needed and with all the library dependences solved.
If you want use Cygwin you will also need cmake. In this case cmake will build a Makefile file that you can use with thie command make.
Installation
on UNIX or Cygwin
If cmake detects the plugin MySQL's directory the command "make -install" will copy the library to the correct folder. If not you can copy the library to this folder manually. Ensure that MySQL can execute this file and his library dependences.
Execute script MySpatialUDF.sql as a mysql administrator.
WARNING !!
This script drop and creates several tables and procedures in mysql schema.
Ensure that you don't delete any table or procedure that is useful !!!!
on WINDOWS
Copy Release/MySpatialUDF.dll and dependent libraries to \lib\plugin
Execute script MySpatialUDF.sql as a mysql administrator.
WARNING !!
This script drop and creates several tables and procedures in mysql schema.
Ensure that you don't delete any table or procedure that is useful !!!!
If you don't like write in mysql schema you can change the first line of the script.
Current Function List Support
+-------------------------------+--------+-------+
| Function | native | msudf |
+-------------------------------+--------+-------+
| ST_Area | Y | N |
| ST_AsBinary | Y | N |
| ST_AsText | Y | N |
| ST_Boundary | N | Y |
| ST_Buffer | N | Y |
| ST_Centroid | N | Y |
| ST_Contains | N | Y |
| ST_ConvexHull | N | Y |
| ST_Crosses | N | Y |
| ST_Difference | N | Y |
| ST_Dimension | Y | N |
| ST_Disjoint | N | Y |
| ST_EndPoint | Y | N |
| ST_Envelope | Y | N |
| ST_ExteriorRing | Y | N |
| ST_GeomFromText | Y | N |
| ST_GeomFromWKB | Y | N |
| ST_GeometryN | Y | N |
| ST_GeometryType | Y | N |
| ST_InteriorRingN | Y | N |
| ST_Intersection | N | Y |
| ST_Intersects | N | Y |
| ST_IsClosed | Y | N |
| ST_IsEmpty | N | Y |
| ST_IsRing | N | Y |
| ST_IsSimple | N | Y |
| ST_IsValid | N | Y |
| ST_Length | Y | N |
| ST_Length2D | Y | N |
| ST_LineMerge | N | Y |
| ST_Line_Substring | N | Y |
| ST_NumGeometries | Y | N |
| ST_NumInteriorRings | Y | N |
| ST_NumPoints | Y | N |
| ST_Overlaps | N | Y |
| ST_PointN | Y | N |
| ST_PointOnSurface | N | Y |
| ST_Reverse | N | Y |
| ST_SRID | Y | N |
| ST_Simplify | N | Y |
| ST_SimplifyPreserveTopology | N | Y |
| ST_SymDifference | N | Y |
| ST_Touches | N | Y |
| ST_Transform | N | Y |
| ST_Union | N | Y |
| ST_Within | N | Y |
| ST_X | Y | N |
| ST_Y | Y | N |
+-------------------------------+--------+-------+
Note: Native functions don't have 'ST_' prefix.
Sample Usage
You can load a table with GDAL tool ogr2ogr.
After this check the SRID of the geometry is correct.
mysql> select srid(geom) into @srid from geom_table limit 1;
Query OK, 1 row affected (0.00 sec)
mysql> select @srid;
+-------+
| @srid |
+-------+
| 3395 |
+-------+
1 row in set (0.00 sec)
mysql> select @srid;
+-------+
| @srid |
+-------+
| 3395 |
+-------+
1 row in set (0.00 sec)
mysql> select auth_name,auth_srid,ref_sys_name from mysql.spatial_ref_sys where
srid = @srid;
+-----------+-----------+-------------------------+
| auth_name | auth_srid | ref_sys_name |
+-----------+-----------+-------------------------+
| epsg | 3395 | WGS 84 / World Mercator |
+-----------+-----------+-------------------------+
1 row in set (0.00 sec)
If it's wrong you can change the SRID value (without transform) with this update:
mysql> update geom_table set geom = GeomFromWKB(aswkb(geom),3395);
You can create another geometry with different projection with this sentence:
mysql> alter table geom_table add column (geom2 geometry);
Query OK, 1 row affected (0.13 sec)
Records: 1 Duplicates: 0 Warnings: 0
mysql> update test set geom2 = mysql.transform(geom,4326);
Query OK, 1 row affected (0.00 sec)
Rows matched: 1000 Changed: 1000 Warnings: 0
Copyright
Copyright (c) 2012, Albert Rovira.
This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.
This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
You should have received a copy of the GNU General Public License along with this program (COPYING.txt). If not, see http://www.gnu.org/licenses/.