Benjamin,<br><br>The mssql driver already does the conversion from wkb in the database to the native ogr geometry format. You don't have to create a temporary wkb geometry and then the ogr geometry.<br><br>You can simply do this:<br>
[code]<br>Geometry memGeom = memFeature.GetGeometryRef()<br>[/code]<br><br><div class="gmail_quote">On Wed, Jul 18, 2012 at 6:31 PM, Benjamin <span dir="ltr"><<a href="mailto:benjamin.lux@maxsea.fr" target="_blank">benjamin.lux@maxsea.fr</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">Sorry, I was not clear.<br>
<br>
I resume from the beginning.<br>
<br>
I work with a warper C# of Ogr.<br>
I have a table dbo.MY_TABLE with 3 fields (D, CHART_ID, WKB_GEOMETRY) in a<br>
SQL server Database (in SQL Azure exactly).<br>
<br>
*My aim is to work with a copy* (in a<br>
<a href="http://www.gdal.org/ogr/drv_memory.html" target="_blank">http://www.gdal.org/ogr/drv_memory.html</a> Memory DataSource ) of a SQL<br>
statement result executed on a MSSQL DataSource.<br>
<br>
Actually I can work with usuals methods with this MSSQL DataSource.<br>
Note that I have not geometry_column table in my SQL Serveur DataBase, I use<br>
<a href="http://www.gdal.org/ogr/drv_mssqlspatial.html" target="_blank">http://www.gdal.org/ogr/drv_mssqlspatial.html</a> driver options .<br>
<br>
[code]<br>
string driverOptions =<br>
"Tables=dbo.MY_TABLE(WKB_GEOMETRY);GeometryFormat=wkb;"<br>
serverDataSource = Ogr.Open("MSSQL:" + connectionString + driverOptions),<br>
0);<br>
<br>
serveurDataSource.GetLayerCount(); // It works fine.<br>
[/code]<br>
<br>
So I tried a call to<br>
<a href="http://www.gdal.org/ogr/classOGRDataSource.html#aa6acc228db6513784a56ce12334a8c33" target="_blank">http://www.gdal.org/ogr/classOGRDataSource.html#aa6acc228db6513784a56ce12334a8c33</a><br>
SQLExecute() .<br>
[code]<br>
string request = "*SELECT * FROM MY_TABLE WHERE CHART_ID = 'ID'*"<br>
<div class="im">Layer serverLayer = serverDataSource.ExecuteSQL(request, null, "");<br>
[/code]<br>
<br>
</div>But unfortunately, I have not geometry field in the result.<br>
[code]<br>
serveurLayer.GetGeometryColumn(); //*return ""*<br>
serveurLayer.GetGeomType(); //*return wkbUnknown*<br>
[/code]<br>
<br>
But I have my 3 fields in serveurLayer !<br>
[code]<br>
serverLayer.GetLayerDefn().GetFieldCount(); //return 3<br>
serverLayer.GetLayerDefn().GetFieldDefn(0).GetName(); //return "D"<br>
serverLayer.GetLayerDefn().GetFieldDefn(1).GetName(); //return "CHART_ID"<br>
serverLayer.GetLayerDefn().GetFieldDefn(2).GetName(); //*return<br>
"WKB_GEOMETRY"*<br>
[/code]<br>
<br>
So I want to copy this layer in a Memory Layer to minimise acces to my SQL<br>
Server and work faster.<br>
[code]<br>
Driver memDriver = Ogr.GetDriverByName("Memory");<br>
DataSource memDataSource =<br>
memDriver.CreateDataSource(GetWorkPath("nomimprobale"), null);<br>
Layer memLayer = memDataSource.CopyLayer(serverLayer, layerName, null);<br>
[/code]<br>
<br>
<br>
Now,* I have to fetch my geometries*, so have thought to a trick like this :<br>
<div class="im">[code]<br>
byte[] memWkb =<br>
System.Text.Encoding.UTF8.GetBytes(memFeature.GetFieldAsString("WKB_GEOMETRY"));<br>
Geometry memGeom = Geometry.CreateFromWkb(memWkb);<br>
[/code]<br>
</div>Because I can't use memFeature.GetGeometryRef()<br>
[code]<br>
memFeature.GetLayerCount(); // return 39<br>
Feature memFeature = memLayer.GetNextFeature(); // don't return null<br>
memFeature.GetGeometryRef(); // *return null*<br>
[/code]<br>
<br>
But I don't know if I have to use UTF8, ASCII, Unicode or other.<br>
If you know what encoding is use, or better an other trick to have a<br>
geometry in my memLayer or serverLayer I heard you with interest !<br>
<br>
<br>
Sorry for my spelling, English isn't my native tongue language.<br>
<br>
Benjamin<br>
<br>
<br>
Ps : link to the thread:<br>
<a href="http://osgeo-org.1560.n6.nabble.com/gdal-dev-Ogr-ExecuteSQL-with-MSSQL-and-geometry-column-tp4988831.html" target="_blank">http://osgeo-org.1560.n6.nabble.com/gdal-dev-Ogr-ExecuteSQL-with-MSSQL-and-geometry-column-tp4988831.html</a><br>
<a href="http://osgeo-org.1560.n6.nabble.com/gdal-dev-Ogr-ExecuteSQL-with-MSSQL-and-geometry-column-tp4988831.html" target="_blank">http://osgeo-org.1560.n6.nabble.com/gdal-dev-Ogr-ExecuteSQL-with-MSSQL-and-geometry-column-tp4988831.html</a><br>
<br>
<br>
<br>
Even Rouault wrote<br>
><br>
> Selon Benjamin <benjamin.lux@>:<br>
<div class="im">><br>
>> "You can access the geometry like with any other ogr feature."<br>
>><br>
><br>
> Hopefully, memFeature.GetGeometryRef() should do it !<br>
> _______________________________________________<br>
> gdal-dev mailing list<br>
</div>> gdal-dev@.osgeo<br>
> <a href="http://lists.osgeo.org/mailman/listinfo/gdal-dev" target="_blank">http://lists.osgeo.org/mailman/listinfo/gdal-dev</a><br>
><br>
<br>
<br>
--<br>
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</div></div></blockquote></div><br><br clear="all"><br>-- <br>Best regards,<br>Chaitanya kumar CH.<br><br>+91-9494447584<br>17.2416N 80.1426E<br>