[SOLVED] Expand a point by a specific number of miles

Expand a point by a specific number of miles

So I have a Geography type spatial column in SQL Server. This represents lat/long coordinates as a single point

Values look like this (as a string)

 POINT (-96.63 32.97)

What I want to do is expand it into a circle/polygon by a specific number of miles. I think STBuffer is the command I want, but I have no idea how to use it expand the radius by X number of miles.

My goal is to then later do STContains on it to see if some other geography object is contained inside of it. Something like this:

    WHERE L.SPATIAL_OBJ.STContains(IBL.SPATIAL_OBJ) = 1

Solution

I figured it out. It looks like this. I would do it as a function.

    CREATE FUNCTION [dbo].[udf_mile_ring]
    (
        @lat FLOAT,
        @lon FLOAT,
        @miles int
    )
    RETURNS GEOGRAPHY
    AS
    BEGIN

        DECLARE @meters FLOAT = @miles / 0.000621371;
        RETURN GEOGRAPHY::Point(@lat, @lon, 4326).STBuffer(@meters);

    END
    GO