使用SQL地理位置获取某个半径的位置

Question

我有一个带有Geography类型的SQL表列:

create table dbo.Events
(
  Id int identity not null 
    constraint PK_Events_Id primary key clustered (Id),
  Localization geography not null
);

我怎样才能获得半径为40公里的所有活动？这可能吗？

谢谢你,米格尔

Answer 1

假设您有要搜索的点的纬度和经度:

DECLARE @Origin GEOGRAPHY,
        -- distance defined in meters
        @Distance INTEGER = 40000;        

-- center point
SET @Origin = GEOGRAPHY::STGeomFromText('POINT(-122.084039 37.42227)', 4326);

-- return all rows from events in 40km radius
SELECT * FROM dbo.Events WHERE @Origin.STDistance(Localizaton) <= @Distance;