sqlhelper.cs

.net数据库操作类源码.分别有ms sql server , oracle , ole db , Npg的数据

		/// <summary>
		/// Execute a SqlCommand (that returns a resultset and takes no parameters) against the provided SqlConnection
		/// and SqlTransaction. 
		/// </summary>
		/// <remarks>
		/// e.g.:  
		///  DataSet ds = ExecuteDataset(conn, trans, CommandType.StoredProcedure, "GetOrders");
		/// </remarks>
		/// <param name="connection">a valid SqlConnection</param>
		/// <param name="transaction">a valid SqlTransaction associated with the connection</param>
		/// <param name="commandType">the CommandType (stored procedure, text, etc.)</param>
		/// <param name="commandText">the stored procedure name or T-SQL command</param>
		/// <returns>a dataset containing the resultset generated by the command</returns>
		public static DataSet ExecuteDataset(SqlConnection connection, SqlTransaction transaction, CommandType commandType, string commandText)
		{
			//pass through the call providing null for the set of SqlParameters
			return ExecuteDataset(connection, transaction, commandType, commandText, (SqlParameter[])null);
		}
		
		/// <summary>
		/// Execute a SqlCommand (that returns a resultset) against the specified SqlConnection and SqlTransaction
		/// using the provided parameters.
		/// </summary>
		/// <remarks>
		/// e.g.:  
		///  DataSet ds = ExecuteDataset(conn, trans, CommandType.StoredProcedure, "GetOrders", new SqlParameter("@prodid", 24));
		/// </remarks>
		/// <param name="connection">a valid SqlConnection</param>
		/// <param name="transaction">a valid SqlTransaction associated with the connection</param>
		/// <param name="commandType">the CommandType (stored procedure, text, etc.)</param>
		/// <param name="commandText">the stored procedure name or T-SQL command</param>
		/// <param name="commandParameters">an array of SqlParamters used to execute the command</param>
		/// <returns>a dataset containing the resultset generated by the command</returns>
		public static DataSet ExecuteDataset(SqlConnection connection, SqlTransaction transaction, CommandType commandType, string commandText, params SqlParameter[] commandParameters)
		{
			//create a command and prepare it for execution
			SqlCommand cmd = new SqlCommand();
			PrepareCommand(cmd, connection, transaction, commandType, commandText, commandParameters);
			
			//create the DataAdapter & DataSet
			SqlDataAdapter da = new SqlDataAdapter(cmd);
			DataSet ds = new DataSet();

			//fill the DataSet using default values for DataTable names, etc.
			da.Fill(ds);
			
			//return the dataset
			return ds;
		}
		
		/// <summary>
		/// Execute a stored procedure via a SqlCommand (that returns a resultset) against the specified SqlConnection 
		/// and SqlTransaction using the provided parameter values.  This method will discover the parameters for the 
		/// stored procedure, and assign the values based on parameter order.
		/// </summary>
		/// <remarks>
		/// This method provides no access to output parameters or the stored procedure's return value parameter.
		/// 
		/// e.g.:  
		///  DataSet ds = ExecuteDataset(conn, trans, "GetOrders", 24, 36);
		/// </remarks>
		/// <param name="connection">a valid SqlConnection</param>
		/// <param name="transaction">a valid SqlTransaction associated with the connection</param>
		/// <param name="spName">the name of the stored prcedure</param>
		/// <param name="parameterValues">an array of objects to be assigned as the input values of the stored procedure</param>
		/// <returns>a dataset containing the resultset generated by the command</returns>
		public static DataSet ExecuteDataset(SqlConnection connection, SqlTransaction transaction, string spName, params object[] parameterValues)
		{
			//if we got parameter values, we need to figure out where they go
			if ((parameterValues != null) && (parameterValues.Length > 0)) 
			{
				//pull the parameters for this stored procedure from the parameter cache (or discover them & populet the cache)
				SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connection.ConnectionString, spName);

				//assign the provided values to these parameters based on parameter order
				AssignParameterValues(commandParameters, parameterValues);

				//call the overload that takes an array of SqlParameters
				return ExecuteDataset(connection, transaction, CommandType.StoredProcedure, spName, commandParameters);
			}
			//otherwise we can just call the SP without params
			else 
			{
				return ExecuteDataset(connection, transaction, CommandType.StoredProcedure, spName);
			}
		}

		#endregion ExecuteDataSet
		
		#region ExecuteReader

		/// <summary>
		/// this enum is used to indicate weather the connection was provided by the caller, or created by SqlHelper, so that
		/// we can set the appropriate CommandBehavior when calling ExecuteReader()
		/// </summary>
		private enum SqlConnectionOwnership	
		{
			/// <summary>Connection is owned and managed by SqlHelper</summary>
			Internal, 
			/// <summary>Connection is owned and managed by the caller</summary>
			External
		}

		/// <summary>
		/// Create and prepare a SqlCommand, and call ExecuteReader with the appropriate CommandBehavior.
		/// </summary>
		/// <remarks>
		/// If we created and opened the connection, we want the connection to be closed when the DataReader is closed.
		/// 
		/// If the caller provided the connection, we want to leave it to them to manage.
		/// </remarks>
		/// <param name="connection">a valid SqlConnection, on which to execute this command</param>
		/// <param name="transaction">a valid SqlTransaction, or 'null'</param>
		/// <param name="commandType">the CommandType (stored procedure, text, etc.)</param>
		/// <param name="commandText">the stored procedure name or T-SQL command</param>
		/// <param name="commandParameters">an array of SqlParameters to be associated with the command or 'null' if no parameters are required</param>
		/// <param name="connectionOwnership">indicates weather the connection parameter was provided by the caller, or created by SqlHelper</param>
		/// <returns>SqlDataReader containing the results of the command</returns>
		private static SqlDataReader ExecuteReader(SqlConnection connection, SqlTransaction transaction, CommandType commandType, string commandText, SqlParameter[] commandParameters, SqlConnectionOwnership connectionOwnership)
		{	
			//create a command and prepare it for execution
			SqlCommand cmd = new SqlCommand();
			PrepareCommand(cmd, connection, transaction, commandType, commandText, commandParameters);
			
			//create a reader
			SqlDataReader dr;

			// call ExecuteReader with the appropriate CommandBehavior
			if (connectionOwnership == SqlConnectionOwnership.External)
			{
				dr = cmd.ExecuteReader();
			}
			else
			{
				dr = cmd.ExecuteReader(CommandBehavior.CloseConnection);
			}

			return dr;
		}


		/// <summary>
		/// Execute a SqlCommand (that returns a resultset and takes no parameters) against the database specified in 
		/// the connection string. 
		/// </summary>
		/// <remarks>
		/// e.g.:  
		///  SqlDataReader dr = ExecuteReader(connString, CommandType.StoredProcedure, "GetOrders");
		/// </remarks>
		/// <param name="connectionString">a valid connection string for a SqlConnection</param>
		/// <param name="commandType">the CommandType (stored procedure, text, etc.)</param>
		/// <param name="commandText">the stored procedure name or T-SQL command</param>
		/// <returns>a SqlDataReader containing the resultset generated by the command</returns>
		public static SqlDataReader ExecuteReader(string connectionString, CommandType commandType, string commandText)
		{
			//pass through the call providing null for the set of SqlParameters
			return ExecuteReader(connectionString, commandType, commandText, (SqlParameter[])null);
		}


		/// <summary>
		/// Execute a SqlCommand (that returns a resultset) against the database specified in the connection string 
		/// using the provided parameters.
		/// </summary>
		/// <remarks>
		/// e.g.:  
		///  SqlDataReader dr = ExecuteReader(connString, CommandType.StoredProcedure, "GetOrders", new SqlParameter("@prodid", 24));
		/// </remarks>
		/// <param name="connectionString">a valid connection string for a SqlConnection</param>
		/// <param name="commandType">the CommandType (stored procedure, text, etc.)</param>
		/// <param name="commandText">the stored procedure name or T-SQL command</param>
		/// <param name="commandParameters">an array of SqlParamters used to execute the command</param>
		/// <returns>a SqlDataReader containing the resultset generated by the command</returns>
		public static SqlDataReader ExecuteReader(string connectionString, CommandType commandType, string commandText, params SqlParameter[] commandParameters)
		{
			//create & open a SqlConnection
			SqlConnection cn = new SqlConnection(connectionString);
			cn.Open();

			try
			{
				//call the private overload that takes an internally owned connection in place of the connection string
				return ExecuteReader(cn, null, commandType, commandText, commandParameters,SqlConnectionOwnership.Internal);
			}
			catch
			{
				//if we fail to return the SqlDatReader, we neeed to close the connection ourselves
				cn.Close();
				throw;
			}
		}

		/// <summary>
		/// Execute a stored procedure via a SqlCommand (that returns a resultset) against the database specified in 
		/// the conneciton string using the provided parameter values.  This method will discover the parameters for the 
		/// stored procedure, and assign the values based on parameter order.
		/// </summary>
		/// <remarks>
		/// This method provides no access to output parameters or the stored procedure's return value parameter.
		/// 
		/// e.g.:  
		///  SqlDataReader dr = ExecuteReader(connString, "GetOrders", 24, 36);
		/// </remarks>
		/// <param name="connectionString">a valid connection string for a SqlConnection</param>
		/// <param name="spName">the name of the stored prcedure</param>
		/// <param name="parameterValues">an array of objects to be assigned as the input values of the stored procedure</param>
		/// <returns>a SqlDataReader containing the resultset generated by the command</returns>
		public static SqlDataReader ExecuteReader(string connectionString, string spName, params object[] parameterValues)
		{
			//if we got parameter values, we need to figure out where they go
			if ((parameterValues != null) && (parameterValues.Length > 0)) 
			{
				//pull the parameters for this stored procedure from the parameter cache (or discover them & populet the cache)
				SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connectionString, spName);

				//assign the provided values to these parameters based on parameter order
				AssignParameterValues(commandParameters, parameterValues);

				//call the overload that takes an array of SqlParameters
				return ExecuteReader(connectionString, CommandType.StoredProcedure, spName, commandParameters);
			}
			//otherwise we can just call the SP without params
			else 
			{
				return ExecuteReader(connectionString, CommandType.StoredProcedure, spName);
			}
		}

		/// <summary>
		/// Execute a SqlCommand (that returns a resultset and takes no parameters) against the provided SqlConnection. 
		/// </summary>
		/// <remarks>
		/// e.g.:  
		///  SqlDataReader dr = ExecuteReader(conn, CommandType.StoredProcedure, "GetOrders");
		/// </remarks>
		/// <param name="connection">a valid SqlConnection</param>
		/// <param name="commandType">the CommandType (stored procedure, text, etc.)</param>
		/// <param name="commandText">the stored procedure name or T-SQL command</param>
		/// <returns>a SqlDataReader containing the resultset generated by the command</returns>
		public static SqlDataReader ExecuteReader(SqlConnection connection, CommandType commandType, string commandText)
		{
			//pass through the call using a null transaction value
			return ExecuteReader(connection, null, commandType, commandText);
		}

		/// <summary>
		/// Execute a SqlCommand (that returns a resultset) against the specified SqlConnection 
		/// using the provided parameters.
		/// </summary>
		/// <remarks>
		/// e.g.:  
		///  SqlDataReader dr = ExecuteReader(conn, CommandType.StoredProcedure, "GetOrders", new SqlParameter("@prodid", 24));
		/// </remarks>