MySQL GIS – Part 1

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In my business (weather) we use lots map based (Geo) information.  Almost every table has latitude and longitude. Working with this kind of data can be exciting and frustrating.  This should give you a quick start into GIS with MySQL.

“A geographic information system (GIS), or geographical information system, is any system that captures, stores, analyzes, manages, and presents data that are linked to location. In the simplest terms, GIS is the merging of cartography, statistical analysis, and database technology. GIS systems are used in cartography, remote sensing, land surveying, utility management, natural resource management, photogrammetry, geography, urban planning, emergency management, navigation, and localized search engines.” – Wikipedia

GIS / Mapping Systems work with both text data and graphical data.  Applications and utilities often blur the lines between the two types and make understanding difficult.  Map servers blend raster images, with point or polygon data, and bitmap images to make complete images to display in the user’s client application.  For this post I will concentrate on the text type “data”.  The type we can index in a MySQL database.

THE SEARCH

After months of reading, [1]  I’m writing this post to describes what I have learned about how to get started using GEO coding data as quickly as possible.  I found very little piratical information on GIS and MySQL.  The MySQL manual covers the functions but doesn’t supply much practical information on GEO.  Anders Karlsson wrote a nice and short story about GIS that give me a good start.

The best information has be written by Florin Duroiu in his post titled “Political boundaries overlay in Google maps”. A good part of my post is based on his work.

STEP BY STEP

Below are the detailed needed to to produce a MySQL database with the Points of Interest (POI).  This is based on CentOS 5.5 with MySQL 5.1.

yum install gdal
mkdir geo
mkdir data
mkdir data/Oklahoma
cd geo/data/Oklahoma
wget http://downloads.cloudmade.com/north_america/united_states/oklahoma/oklahoma.shapefiles.zip
unzip oklahoma.shapefiles.zip
mysql -e 'create database geo'
ogr2ogr -f "MySQL" MySQL:"geo,user=root,host=localhost,password=" -nln oklahoma_poi -lco engine=MYISAM oklahoma_poi.shp
mysql geo -e 'desc oklahoma_poi'

+----------+--------------+------+-----+---------+----------------+
| Field    | Type         | Null | Key | Default | Extra          |
+----------+--------------+------+-----+---------+----------------+
| OGR_FID  | int(11)      | NO   | PRI | NULL    | auto_increment |
| SHAPE    | geometry     | NO   | MUL | NULL    |                |
| category | varchar(30)  | YES  |     | NULL    |                |
| name     | varchar(113) | YES  |     | NULL    |                |
+----------+--------------+------+-----+---------+----------------+

mysql geo -e "select name, category, Y(SHAPE) as lat, X(SHAPE) as lng  from oklahoma_poi where NAME like 'School:Putnam%'"

+-------------------------------------+--------------------------------+------------+-------------+
| name                                | category                       | lat        | lng         |
+-------------------------------------+--------------------------------+------------+-------------+
| School:Putnam City West High School | Government and Public Services |  35.492557 | -97.6605975 |
| School:Putnam City North School     | Government and Public Services | 35.5892209 | -97.6372648 |
| School:Putnam City School           | Government and Public Services | 35.5122794 | -97.6142079 |
| School:Putnam High School           | Government and Public Services | 35.5214459 | -97.6086523 |
| School:Putnam Heights Academy       | Government and Public Services | 35.5081143 | -97.5397619 |
+-------------------------------------+--------------------------------+------------+-------------+

In a coming set of post I’ll go over:

• The “Data” types your will find and how to convert between them.
• What data is available and where can you find it?
• More examples on what you can do with GIS data.
• Viewing our GIS data.
• How to collect your own GIS data.
• Good and bad examples of searching GIS data.
• Optimizing MySQL GIS.  Is it really worth using?

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[1] Books: GIS for Dummies – Author: Michael N. DeMers – John Wiley & Sons (2009) – ISBN: 0470236825
Open Source GIS: A GRASS GIS Approach. Third Edition.-  Author: Markus Neteler and Helena Mitasova – ISBN: 978-0-38735767-6
Web Mapping Illustrated: Using Open Source GIS Toolkits – Author: Tyler Mitchell – ISBN: 9780596008659