Spatial Functions

PostGIS provides a set of spatial functions that can be used within SQL queries in order to operate on the geometries stored within a table. These functions allow you to perform many common GIS operations and analysis on the data stored in your database. You should become familiar with the most common functions and be comfortable looking up the documentation for functions you havent used before.

Goals/Objectives/Outcomes

• Understand the wide range of functions provided by PostGIS that conform to the SQL-MM standard
• Understand how aggregate functions are used
• Understand how PostGIS management functions are used to perform basic admin tasks and to inspect your PostGIS configuration
• Understand how to use Geometry constructors to convert between different types and formats of data
• Understand how to use Geometry accessors to inspect spatial data attributes
• Understand how to use spatial functions in a SQL Query

Reference Material

• http://postgis.net/docs/PostGIS_Special_Functions_Index.html
• http://postgis.net/docs/reference.html
• http://www.bostongis.com/PrinterFriendly.aspx?content_name=postgis_tut02
• http://www.gistutor.com/postgresqlpostgis/10-intermediate-postgresqlpostgis-tutorials/75-understanding-postgis-spatial-queries.html
• http://revenant.ca/www/postgis/workshop/advanced.html
• http://manual.linfiniti.com/en/postgis/spatial_queries.html

Measures of Success

• Participant has become familiar with the range of spatial functions and can articulate the differences between the different types and describe how they are used
• Participant has demonstrated the ability to use spatial functions in SQL Queries
• Participant has demonstrated the ability to use geometry constructors, accessors and editors to work with spatial data attributes
• Participant has become familiar with the documentation for PostGIS spatial functions and explored unfamiliar functions