Question

We are working on one map solution.
Here user has drawn one polygon on the map and for a given point we need to find if point is residing in or out of the polygon.

We are using one SQL technique as per http://www.sql-statements.com/point-in-polygon.html to do this task till now but during the time we found out that its not worked for some areas.

Does anyone has the proper solution on this? We can also try the solution in C# if its working fine

Thank you.

Answer 1

If you are using SQL Server 2008 then you can use STIntersection (geography Data Type) – SQL Server will do everything for you.

I’d recommend SQL Server 2008 in this case because it provides native support for geographical data. Before you use it “STIntersect giving incorrect result for geography Datatype” might be worth of reading. Example from that site:

declare @point geometry
declare @polygon geometry
set @point =  geometry::STGeomFromText('POINT (-88.22 41.50000001)', 4326)
set @polygon = geometry::STGeomFromText('POLYGON ((-88.2 41.5, -88.2 41.6, -88.3 41.6, -88.3 41.5, -88.2 41.5))', 4326)--124
Select @point.STIntersection(@polygon).ToString()