<p>Hi all,</p><p>According to page <a href="http://www.gdal.org/ogr/ogr_sql.html">http://www.gdal.org/ogr/ogr_sql.html</a> , I found that <strong><</strong>, <b>></b>, <b><=</b> and <b>>=</b> operators <em>are</em> case sensitive. My code is something like this: and I couldn't get the required result. Can anyone give me some suggestions?Thanks for your help!</p><div>  OGRFeature *pfea = OGRFeature::CreateFeature(poLayerws->GetLayerDefn());<br>  pfea->SetField("codede","CAPITAL");<br>  if (poLayerws->CreateFeature(pfea) != OGRERR_NONE)<br>  {<br>   return false;<br>  }<br>  pfea = OGRFeature::CreateFeature(poLayerws->GetLayerDefn());<br>  pfea->SetField("codede","capital");<br>  if (poLayerws->CreateFeature(pfea) != OGRERR_NONE)<br>  {<br>   return false;<br>  }<br> string layername = poLayerws->GetName();<br> string ssf = "SELECT * FROM " + layername + " WHERE codede >= 'capital' AND codede <= 'capital'" ;<br> const char *sql = ssf.c_str();<br> OGRLayer *ret = poDSws->ExecuteSQL(sql,NULL,NULL);</div><div>/*value of n is  2*/<br> int n = ret->GetFeatureCount();<br> ret->ResetReading();<br> OGRFeature *pfearet;</div><div>/*prints CAPITAL </div><div>capital*/<br> while(pfearet = ret->GetNextFeature())<br> {<br>  cout<<pfearet->GetFieldAsString("codede")<<endl;<br> }</div><div>poDSws->ReleaseResultSet(ret);</div><div> OGRDataSource::DestroyDataSource(poDSws);<br> OGRCleanupAll();</div>