Showing posts with label postgis. Show all posts
Showing posts with label postgis. Show all posts

28 August 2009

Which location column more trusted?

You have database from your client with fields state, district (description of locations), and the_geom (latitude/longitude) column. Example of the db

| state | district | the_geom |
| Selangor | Petaling | POINT(101.497838106615 3.27468487066054) |


Anyone doing GIS should know that, the state, district fields is duplicate with the_geom since once we know the latitude/longitude we will know the state, district.
The problem is the_geom is not within Selangor, Petaling. Then when do group by st_intersects, the value is wrong since the_geom is refer to other place!

So, need to decide, which location column more trusted?
The latitude/longitude or description of locations.