private void LoadSchema(DataSet ds, WmiCommand command, WmiDataReader reader)
{
//Match the query "table".
string name = _commandtable.Match(command.CommandText).Groups["table"].Value;
if (ds.Tables.Contains(name))
{
ds.Tables.Remove(name);
}
DataTable table = new DataTable(name);
//Use the first object to build the table structure.
ManagementObject one = reader.GetOne();
if (one != null)
{
foreach (PropertyData prop in one.Properties)
{
table.Columns.Add(prop.Name, WmiConvert.WmiToClr(prop.Type));
}
}
//Add dummy column if no data is found. For consistency with other ADO.NET providers which always load the schema.
if (table.Columns.Count == 0)
{
table.Columns.Add("Object", typeof(string));
}
ds.Tables.Add(table);
}
/// <summary>
/// Executes the WMI query and returns an IDataReader.
/// </summary>
/// <returns>The reader with the results.</returns>
public IDataReader ExecuteReader()
{
if (_connection == null || _connection.State != ConnectionState.Open)
{
throw new InvalidOperationException("The connection must be set and opened in order to execute the command.");
}
if (_query == null || _query == String.Empty)
{
throw new InvalidOperationException("The CommandText must be set in order to execute the command.");
}
// create a reader
WmiDataReader reader = new WmiDataReader(_connection);
ManagementObjectSearcher os = new ManagementObjectSearcher(_connection.Scope, new ObjectQuery(_query));
reader.Data = os.Get();
return(reader);
}
/// <summary>
/// Adds rows in the DataSet to match those in the data source.
/// </summary>
/// <param name="dataSet">A DataSet to fill with records and, if necessary, schema.</param>
/// <returns>The number of rows successfully added to the DataSet.</returns>
public int Fill(DataSet dataSet)
{
if (_select == null || _select.CommandText == String.Empty)
{
throw new InvalidOperationException("Select command doesn't contain a valid query to execute.");
}
//Open connection if needed.
bool doclose = false;
if (_select.Connection.State != ConnectionState.Open)
{
_select.Connection.Open();
doclose = true;
}
WmiDataReader dr = (WmiDataReader)_select.ExecuteReader();
LoadSchema(dataSet, _select, dr);
DataTable tb = dataSet.Tables[_commandtable.Match(_select.CommandText).Groups["table"].Value];
if (tb != null)
{
tb.BeginLoadData();
while (dr.Read())
{
object[] values = new object[dr.FieldCount];
dr.GetValues(values);
tb.LoadDataRow(values, true);
}
}
//Close connection if appropriate.
if (doclose)
{
_select.Connection.Close();
}
return(dr.RecordsAffected);
}
