请教一个using语句的问题

[weixin_38056302]

请问将return放在using语句大括号中和大括号外有区别吗？
放在大括号外会释放资源吗？
public DataRow GetDataRow(string sql)
{
DataTable dataTable = new DataTable();
DataRow dataRow;

using (MySqlDataAdapter dataAdapter = new MySqlDataAdapter())
{
dataAdapter.SelectCommand = new MySqlCommand();
dataAdapter.SelectCommand.Connection = new MySqlConnection(this.ConnectionString);
dataAdapter.SelectCommand.CommandType = CommandType.Text;
dataAdapter.SelectCommand.CommandText = sql;
dataAdapter.SelectCommand.ExecuteScalar();

dataAdapter.Fill(dataTable);
dataRow = dataTable.Rows.Count > 0 ? dataTable.Rows[0] : null;
//return dataRow;
}
return dataRow;
}