cadence封裝庫，封裝DBHelper

封裝DBHelper

封裝的作用：
可以簡化大量代碼

 public class DBHelper{public static string connString;static DBHelper(){connString = ConfigurationManager.AppSettings["connstring"];}/// <summary>/// 對使用ExecuteNonQuery封裝/// </summary>/// <param name="cmdText"></param>/// <param name="parameters"></param>/// <returns></returns>public static int ExecuteNonQuery(string cmdText, params SqlParameter[] parameters){using (SqlConnection connection = new SqlConnection(connString)){connection.Open();using (SqlCommand cmd = new SqlCommand(cmdText, connection)){if (parameters.Length > 0){cmd.Parameters.AddRange(parameters);}return cmd.ExecuteNonQuery();}}}/// <summary>/// 對使用ExecuteScalar的一個封裝/// 使用泛型方法對于這種不確定的數據類型/// </summary>/// <param name="cmdText"></param>/// <param name="parameters"></param>/// <returns></returns>public static T ExecuteScalar<T>(string cmdText, params SqlParameter[] parameters){using (SqlConnection connection = new SqlConnection(connString)){connection.Open();using (SqlCommand cmd = new SqlCommand(cmdText, connection)){if (parameters.Length > 0){cmd.Parameters.AddRange(parameters);}return (T)cmd.ExecuteScalar();}}}public static SqlDataReader ExecuteReader(string cmdText, params SqlParameter[] parameters){using (SqlConnection connection = new SqlConnection(connString)){connection.Open();using (SqlCommand cmd = new SqlCommand(cmdText, connection)){if (parameters.Length > 0){cmd.Parameters.AddRange(parameters);}return cmd.ExecuteReader(CommandBehavior.CloseConnection);}}}/// <summary>/// 獲取臨時庫/// </summary>/// <param name="cmdText"></param>/// <param name="parameters"></param>/// <returns></returns>public static DataSet GetDataSet(string cmdText, params SqlParameter[] parameters){DataSet ds = new DataSet();using (SqlDataAdapter adapter = new SqlDataAdapter(cmdText, connString)){if (parameters.Length > 0){adapter.SelectCommand.Parameters.AddRange(parameters);}adapter.Fill(ds);}return ds;}/// <summary>/// 獲取臨時表/// </summary>/// <param name="cmdText"></param>/// <param name="parameters"></param>/// <returns></returns>public static DataTable GetDataTable(string cmdText, params SqlParameter[] parameters){return GetDataSet(cmdText, parameters).Tables[0];}}