protected override int GetCountCore()
{
int count = 0;
OleDbCommand command = null;
OleDbDataReader dataReader = null;
string sqlStatement = "SELECT COUNT(*) FROM " + tableName;
try
{
command = new OleDbCommand(sqlStatement, connection);
ExecutingSqlStatemenOleDbFeatureSourceEventArgs e = new ExecutingSqlStatemenOleDbFeatureSourceEventArgs(command.CommandText, ExecutingSqlStatementType.GetCount);
OnExecutingSqlStatement(e);
dataReader = command.ExecuteReader();
if (dataReader.Read())
{
count = Convert.ToInt32(dataReader[0], CultureInfo.InvariantCulture);
}
}
finally
{
if (dataReader != null)
{
dataReader.Dispose();
}
if (command != null)
{
command.Connection.Close();
command.Dispose();
}
}
return(count);
}
protected virtual void OnExecutingSqlStatement(ExecutingSqlStatemenOleDbFeatureSourceEventArgs e)
{
EventHandler <ExecutingSqlStatemenOleDbFeatureSourceEventArgs> handler = ExecutingSqlStatement;
if (handler != null)
{
handler(this, e);
}
}
protected override Collection <Feature> GetAllFeaturesCore(IEnumerable <string> returningColumnNames)
{
OleDbCommand command = null;
OleDbDataReader dataReader = null;
Collection <Feature> returnFeatures = new Collection <Feature>();
try
{
command = new OleDbCommand("SELECT " + featureIdColumn + " as TG_ID, " + wkbFieldName + " as TG_Wkb FROM " + tableName, connection);
ExecutingSqlStatemenOleDbFeatureSourceEventArgs e = new ExecutingSqlStatemenOleDbFeatureSourceEventArgs(command.CommandText, ExecutingSqlStatementType.GetAllFeatures);
OnExecutingSqlStatement(e);
command.CommandText = e.SqlStatement;
dataReader = command.ExecuteReader();
while (dataReader.Read())
{
byte[] wkb = Convert.FromBase64String(dataReader["TG_Wkb"].ToString());
Feature feature = new Feature(wkb, dataReader["TG_ID"].ToString());
foreach (string columnName in returningColumnNames)
{
feature.ColumnValues.Add(columnName, dataReader[columnName].ToString());
}
returnFeatures.Add(feature);
}
}
finally
{
if (command != null)
{
command.Dispose();
}
if (dataReader != null)
{
dataReader.Dispose();
}
}
return(returnFeatures);
}
private void OleDbFeature_ExecutingSqlStatement(object sender, ExecutingSqlStatemenOleDbFeatureSourceEventArgs e)
{
switch (e.ExecutingSqlStatementType)
{
case ExecutingSqlStatementType.GetAllFeatures:
if (tabControl1.SelectedTab == tabPage2)
{
if (radioButton1.Checked)
{
e.SqlStatement += " where TG_ID between 1 and 7000";
}
else if (radioButton2.Checked)
{
e.SqlStatement += " where TG_ID>7001";
}
}
else
{
tbxSqlStr.Text = e.SqlStatement;
tbxType.Text = e.ExecutingSqlStatementType.ToString();
}
break;
case ExecutingSqlStatementType.GetCount:
tbxSqlStr.Text = e.SqlStatement;
tbxType.Text = e.ExecutingSqlStatementType.ToString();
break;
case ExecutingSqlStatementType.GetFirstGeometryType:
tbxSqlStr.Text = e.SqlStatement;
tbxType.Text = e.ExecutingSqlStatementType.ToString();
break;
default:
break;
}
}
public WellKnownType GetFirstGeometryType()
{
OleDbCommand command = null;
OleDbDataReader dataReader = null;
WellKnownType type = WellKnownType.Invalid;
string sqlStatement = string.Format("SELECT TOP 1 {0} FROM {1};", wkbFieldName, tableName);
try
{
command = new OleDbCommand(sqlStatement, connection);
ExecutingSqlStatemenOleDbFeatureSourceEventArgs e = new ExecutingSqlStatemenOleDbFeatureSourceEventArgs(command.CommandText, ExecutingSqlStatementType.GetFirstGeometryType);
OnExecutingSqlStatement(e);
dataReader = command.ExecuteReader();
if (dataReader.Read())
{
if (dataReader[0] != DBNull.Value)
{
type = (new Feature((byte[])(Convert.FromBase64String(dataReader[0].ToString())))).GetWellKnownType();
}
}
}
finally
{
if (dataReader != null)
{
dataReader.Dispose();
}
if (command != null)
{
command.Connection.Close();
command.Dispose();
}
}
return(type);
}
