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Developer that lives by the mantra "code is meant to be shared".




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Microsoft.SqlServer.Types and SQL Server 2012, inconsistency

Daniel WertheimDaniel Wertheim

Been working a bit with Microsoft SQL Server 2012 and spatial features using the Geography data type. I'm using it from ADO.Net hence I make use of the Microsoft.SqlServer.Types library. Didn't take long to get annoyed about the API in there. Let's have a look. There´s a type: SqlGeography; that you can use as a parameter against SQL Server. First I created a simple polygon consisting of some coordinates (don't know where on earth since it's taken from MSDN).

Due to lack of building a polygon from actual instances SqlGeography representing points we need to do it the textual way:

var polygon = new SqlChars("POLYGON((  
    -122.358 47.653, 
    -122.348 47.649, 
    -122.348 47.658, 
    -122.358 47.658, 
    -122.358 47.653))".ToCharArray());

Now we could create a standard parameter for use in our SQL:

var coordsP = (SqlParameter)cmd.CreateParameter();  
coordsP.ParameterName = "pCoords";  
coordsP.Direction = ParameterDirection.Input;  
coordsP.SqlDbType = SqlDbType.Udt;  
coordsP.UdtTypeName = "geography";  
coordsP.Value = SqlGeography.STPolyFromText(polygon, 4326);  

There´s a method: SqlGeography.Point(latitude, longitude, srid); that you could use to create a simple point, it would look something like this:

var point = SqlGeography.Point(  
    47.653, //Latitude 
    -122.358, //Longitude
    4326); //SRID

Lets have a look at the data we inserted using the polygon created above:

    Coords.STAsText() Polygon,
    Coords.STPointN(1).STAsText() Point1,
    Coords.STPointN(1).Lat Point1Latitud,
    Coords.STPointN(1).Long Point1Longitude
from LocationSpatials  


  -122.358 47.653,
  -122.348 47.649,
  -122.348 47.658,
  -122.358 47.658,
  -122.358 47.653

POINT (-122.358 47.653)



Tell me you spot it! These kind of inconsistencies drives me crazy! If I in code define a point with Latitude first and Longitude as the second argument, I sure as hell would expect that to be the layout of the STAsText methods as well. Also, isn't it cutym to have it Latitude, Longitude and not Longitude, Latitude? I hope I'm wrong, otherwise the person doing the STAsText method must have been drunk.


Developer that lives by the mantra "code is meant to be shared".