连接数据库

public class SqlClass
 {
  private string myConnString;
  private SqlConnection myConnection;
  public SqlClass()
  {
   //
   // TODO: 在此处添加构造函数逻辑
   //
  }
  
  
  public void Open()
  {
   myConnString=ConfigurationSettings.AppSettings["ConnectionString"];
   myConnection = new SqlConnection(myConnString);
   myConnection.Open();
  }
  public DataSet GetDataSet(string strCommandString,string strTableName)
  {
   //SqlCommand cmdCommand = new SqlCommand(strCommandString,myConnection);
   
   SqlDataAdapter adAdapter = new SqlDataAdapter();
   adAdapter.SelectCommand = new SqlCommand(strCommandString, myConnection);
   
   DataSet dsDataSet = new DataSet();
   dsDataSet.Clear();
   adAdapter.Fill(dsDataSet,strTableName);
   return dsDataSet;
  }

  public void Close()
  {
   myConnection.Close();
  }
}