/// <summary>
/// Computes a bounding box which covers all geometries in <see cref="Table"/>.
/// </summary>
/// <returns>
/// The bounding box which describes the maximum extents
/// of the data retrieved by the data source.
/// </returns>
public BoundingBox GetExtents()
{
using (PgConnection conn = new PgConnection(_connectionString))
{
string sql = String.Format("SELECT EXTENT({0}) FROM {1}",
GeometryColumn,
Table);
if (!String.IsNullOrEmpty(_defintionQuery))
{
sql += " WHERE " + DefinitionQuery;
}
sql += ";";
using (PgCommand command = new PgCommand(sql, conn))
{
conn.Open();
BoundingBox bbox;
try
{
PgBox2D result = (PgBox2D)command.ExecuteScalar();
bbox =
new BoundingBox(result.LowerLeft.X, result.LowerLeft.Y, result.UpperRight.X,
result.UpperRight.Y);
}
catch (Exception ex)
{
throw new Exception("Box2d couldn't fetched from table. ", ex);
}
finally
{
conn.Close();
}
return(bbox);
}
}
}
private void obtainSpatialReference()
{
// Get the Srid for the table
string sql = "SELECT srid FROM geometry_columns WHERE f_table_name = @Table";
using (PgConnection conn = new PgConnection(_connectionString))
{
using (PgCommand command = new PgCommand(sql, conn))
{
try
{
conn.Open();
command.Parameters.Add(new PgParameter("@Table", PgDbType.VarChar));
command.Parameters[0].Value = Table;
_srid = (int)command.ExecuteScalar();
}
catch (PgException) {}
}
}
}
/// <summary>
/// Returns the number of features in the dataset
/// </summary>
/// <returns>number of features</returns>
public int GetFeatureCount()
{
int count;
using (PgConnection conn = new PgConnection(_connectionString))
{
string sql = "SELECT COUNT(*) FROM " + Table;
if (!String.IsNullOrEmpty(_defintionQuery))
{
sql += " WHERE " + DefinitionQuery;
}
using (PgCommand command = new PgCommand(sql, conn))
{
conn.Open();
count = (int)command.ExecuteScalar();
conn.Close();
}
}
return(count);
}
/// <summary>
/// Queries the PostGIS database to get the name of the Geometry Column. This is used if the columnname isn't specified in the constructor
/// </summary>
/// <remarks></remarks>
/// <returns>Name of column containing geometry</returns>
private string GetGeometryColumn()
{
string strSQL = "select f_geometry_column from geometry_columns WHERE f_table_name = @Table'";
using (PgConnection conn = new PgConnection(_ConnectionString))
using (PgCommand command = new PgCommand(strSQL, conn))
{
conn.Open();
command.Parameters.Add(new PgParameter("@Table", PgDbType.VarChar));
command.Parameters[0].Value = this._Table;
object columnname = command.ExecuteScalar();
conn.Close();
if (columnname == System.DBNull.Value)
{
throw new ApplicationException("Table '" + this.Table + "' does not contain a geometry column");
}
return((string)columnname);
}
}
/// <summary>
/// Returns the number of features in the dataset
/// </summary>
/// <returns>number of features</returns>
public int GetFeatureCount()
{
int count = 0;
using (PgConnection conn = new PgConnection(_ConnectionString))
{
string strSQL = "SELECT COUNT(*) FROM " + this.Table;
if (!String.IsNullOrEmpty(_defintionQuery))
{
strSQL += " WHERE " + this.DefinitionQuery;
}
using (PgCommand command = new PgCommand(strSQL, conn))
{
conn.Open();
count = Convert.ToInt32(command.ExecuteScalar());
conn.Close();
}
}
return(count);
}
/// <summary>
/// Boundingbox of dataset
/// </summary>
/// <returns>boundingbox</returns>
public IEnvelope GetExtents()
{
using (PgConnection conn = new PgConnection(_ConnectionString))
{
string strSQL = String.Format("SELECT EXTENT({0}) FROM {1}",
this.GeometryColumn,
this.Table);
if (!String.IsNullOrEmpty(_defintionQuery))
strSQL += " WHERE " + this.DefinitionQuery;
strSQL += ";";
using (PgCommand command = new PgCommand(strSQL, conn))
{
conn.Open();
IEnvelope bbox = null;
try
{
PostgreSql.Data.PgTypes.PgBox2D result = (PostgreSql.Data.PgTypes.PgBox2D)command.ExecuteScalar();
bbox = SharpMap.Converters.Geometries.GeometryFactory.CreateEnvelope(result.LowerLeft.X, result.UpperRight.X, result.LowerLeft.Y, result.UpperRight.Y);
}
catch (System.Exception ex)
{
throw new Exception("Box2d couldn't fetched from table. " + ex.Message);
}
finally
{
conn.Close();
}
return bbox;
}
}
}
/// <summary>
/// Queries the PostGIS database to get the name of the Geometry Column. This is used if the columnname isn't specified in the constructor
/// </summary>
/// <remarks></remarks>
/// <returns>Name of column containing geometry</returns>
private string GetGeometryColumn()
{
string strSQL = "select f_geometry_column from geometry_columns WHERE f_table_name = @Table'";
using (PgConnection conn = new PgConnection(_ConnectionString))
using (PgCommand command = new PgCommand(strSQL, conn))
{
conn.Open();
command.Parameters.Add(new PgParameter("@Table", PgDbType.VarChar));
command.Parameters[0].Value = this._Table;
object columnname = command.ExecuteScalar();
conn.Close();
if (columnname == System.DBNull.Value)
throw new ApplicationException("Table '" + this.Table + "' does not contain a geometry column");
return (string)columnname;
}
}
/// <summary>
/// Returns the number of features in the dataset
/// </summary>
/// <returns>number of features</returns>
public int GetFeatureCount()
{
int count = 0;
using (PgConnection conn = new PgConnection(_ConnectionString))
{
string strSQL = "SELECT COUNT(*) FROM " + this.Table;
if (!String.IsNullOrEmpty(_defintionQuery))
strSQL += " WHERE " + this.DefinitionQuery;
using (PgCommand command = new PgCommand(strSQL, conn))
{
conn.Open();
count = (int)command.ExecuteScalar();
conn.Close();
}
}
return count;
}
/// <summary>
/// Boundingbox of dataset
/// </summary>
/// <returns>boundingbox</returns>
public BoundingBox GetExtents()
{
using (PgConnection conn = new PgConnection(_ConnectionString))
{
string strSQL = String.Format("SELECT EXTENT({0}) FROM {1}",
GeometryColumn,
Table);
if (!String.IsNullOrEmpty(_defintionQuery))
strSQL += " WHERE " + DefinitionQuery;
strSQL += ";";
using (PgCommand command = new PgCommand(strSQL, conn))
{
conn.Open();
BoundingBox bbox = null;
try
{
PgBox2D result = (PgBox2D) command.ExecuteScalar();
bbox = new BoundingBox(result.LowerLeft.X, result.LowerLeft.Y, result.UpperRight.X,
result.UpperRight.Y);
}
catch (Exception ex)
{
throw new Exception("Box2d couldn't fetched from table. " + ex.Message);
}
finally
{
conn.Close();
}
return bbox;
}
}
}
/// <summary>
/// Boundingbox of dataset
/// </summary>
/// <returns>boundingbox</returns>
public SharpMap.Geometries.BoundingBox GetExtents()
{
using (PgConnection conn = new PgConnection(_ConnectionString))
{
string strSQL = String.Format("SELECT EXTENT({0}) FROM {1}",
this.GeometryColumn,
this.Table);
if (!String.IsNullOrEmpty(_defintionQuery))
{
strSQL += " WHERE " + this.DefinitionQuery;
}
strSQL += ";";
using (PgCommand command = new PgCommand(strSQL, conn))
{
conn.Open();
SharpMap.Geometries.BoundingBox bbox = null;
try
{
PostgreSql.Data.PgTypes.PgBox2D result = (PostgreSql.Data.PgTypes.PgBox2D)command.ExecuteScalar();
bbox = new SharpMap.Geometries.BoundingBox(result.LowerLeft.X, result.LowerLeft.Y, result.UpperRight.X, result.UpperRight.Y);
}
catch (System.Exception ex)
{
throw new Exception("Box2d couldn't fetched from table. " + ex.Message);
}
finally
{
conn.Close();
}
return(bbox);
}
}
}
