/// <summary>
/// Reads the complete feature set from the database
/// </summary>
/// <param name="connString">sqlite db connection string</param>
/// <param name="featureSetInfo">information about the table</param>
/// <param name="sql">the sql query</param>
/// <returns>the resulting feature set</returns>
public IFeatureSet ReadFeatureSet(string connString, GeometryColumnInfo featureSetInfo, string sql)
{
FeatureSet fs = new SpatiaLiteFeatureSet(featureSetInfo.GeometryType);
fs.IndexMode = false; //setting the initial index mode..
using (var cmd = CreateCommand(connString, sql))
{
cmd.Connection.Open();
RunInitialCommands(cmd.Connection);
//DotSpatial.Topology.Utilities.WkbReader wkbr = new DotSpatial.Topology.Utilities.WkbReader();
var wkbr = new SpatiaLiteWkbReader();
var rdr = cmd.ExecuteReader();
var columnNames = PopulateTableSchema(fs, featureSetInfo.GeometryColumnName, rdr);
while (rdr.Read())
{
var wkb = rdr[featureSetInfo.GeometryColumnName] as byte[];
var geom = wkbr.Read(wkb);
var newFeature = fs.AddFeature(geom);
//populate the attributes
foreach (var colName in columnNames)
{
newFeature.DataRow[colName] = rdr[colName];
}
}
cmd.Connection.Close();
fs.Name = featureSetInfo.TableName;
//TODO: look into this more
//HACK required for selection to work properly
fs.IndexMode = true;
//assign projection
var proj = ProjectionInfo.FromEpsgCode(featureSetInfo.SRID);
fs.Projection = proj;
return(fs);
}
}
//finds out the geometry column information..
private GeometryColumnInfo FindGeometryColumnInfo(string connString, string sqlQuery)
{
GeometryColumnInfo result = null;
using (var cmd = CreateCommand(connString, sqlQuery))
{
cmd.Connection.Open();
RunInitialCommands(cmd.Connection);
var wkbr = new SpatiaLiteWkbReader();
var rdr = cmd.ExecuteReader(CommandBehavior.SingleRow);
var schemaTable = rdr.GetSchemaTable();
foreach (DataRow r in schemaTable.Rows)
{
var colName = Convert.ToString(r["ColumnName"]);
var colDataType = Convert.ToString(r["DataType"]);
//if BLOB, then assume geometry column
if (Type.GetType(colDataType) == typeof(byte[]))
{
result = new GeometryColumnInfo();
result.GeometryColumnName = colName;
break;
}
}
if (result != null && rdr.HasRows)
{
rdr.Read();
var blob = rdr[result.GeometryColumnName] as byte[];
var geom = wkbr.Read(blob);
result.GeometryType = GetGeometryType(Convert.ToString(rdr["type"]));
}
cmd.Connection.Close();
return(result);
}
}
