dataaccesslayer.cs

一个经典的apriori算法（c#实现）

using System;
using System.Data;
using System.Data.OleDb;


	/// <summary>
	/// The VISUAL_BASIC_DATA_MINING_NET namespace contains namespaces and classes used by this assembly.
	/// </summary>
namespace VISUAL_BASIC_DATA_MINING_NET
{

	
	/// <summary>
	/// Implements data access to relational databases and XML data stores.
	/// </summary>
	public class DataAccessLayer
	{

		public enum CommandAction 
		{
			deleteCommand = 1,
			insertCommand = 2,
			updateCommand = 3
		}

	
		/// <summary>
		/// A string variable that contains the connection string for relational database access.
		/// </summary>
		protected string connectionString;
		
		/// <summary>
		/// A string variable that contains the path to an XML file.
		/// </summary>
		protected string filePath;
		
		/// <summary>
		/// A System.Data.OleDb.OleDbDataAdapter variable used to execute fill the DataSet with transactions data.
		/// </summary>
		protected OleDbDataAdapter myAdapter;
		
		/// <summary>
		/// A System.Data.OleDb.OleDbCommand variable used to execute a stored procedure or SQL SELECT statement.
		/// </summary>
		protected OleDbCommand myCommand;
		
		/// <summary>
		/// A System.Data.OleDb.OleDbConnection variable representing an open connection to the database.
		/// </summary>
		protected OleDbConnection myConnection;
				
		/// <summary>
		/// A System.Data.DataTable variable that stores transactions data being analyzed.
		/// </summary>
		protected DataTable myTransactionTable;
		
		/// <summary>
		/// A strongly typed System.Data.DataSet object containing an in-memory cache of transaction data.
		/// </summary>
		protected Data myDatabase;


		/// <summary>
		/// A parameterless default constructor that instantiates a new DataAccessLayer object.
		/// </summary>
		public DataAccessLayer()
		{
		}
		
		
		/// <summary>
		/// The connection string for accessing a relational database.
		/// </summary>
		/// <value>
		/// A string value that represents the path to a relational database containing transactions to be analyzed.
		/// </value>
		public string ConnectionString
		{
			get
			{
				return connectionString;
			}

			set
			{
				connectionString = value;
			}			
		}
		

		/// <summary>
		/// The path to an XML file that conatins transactions to be analyzed.
		/// </summary>
		/// <value>
		/// A string value that represents the path a the XML file containing transactions to be analyzed.
		/// </value>
		public string FilePath
		{
			get
			{
				return filePath;
			}

			set
			{
				filePath = value;
			}			
		}

		
		/// <summary>
		/// Retrieves transaction data from an XML file.
		/// </summary>
		/// <param name="xmlFilePath">
		/// The path to of the XML file containing transaction data.
		/// </param>
		/// <returns>
		/// A type safe Data object containing transaction data retrieved from the XML file.
		/// </returns>
		public Data GetXMLData(string xmlFilePath)
		{
			myDatabase = new Data();

			string errorMessage;


			try
			{
				myDatabase.ReadXml(xmlFilePath);
			}

			catch(Exception Ex)
			{
				errorMessage = Ex.ToString();
			}

			return myDatabase;
		}
		
		
		/// <summary>
		/// Retrieves transaction data from TransactionsTable.
		/// </summary>
		/// <param name="rdbmsConnectionString">
		/// The connection string used to establish connection to a relational database using ADO.NET.
		/// <example>
		/// An example of a connection string using Windows Integrated Security :
		/// <para>
		/// string connect = "Provider=SQLOLEDB;Data Source=localhost;Initial Catalog=Sales;" + "Integrated Security=SSPI;";
		/// </para>
		/// An example of a string not using Windows Integrated Security : 
		/// <para>
		/// "Provider=SQLOLEDB;Data Source=localhost;User ID=Analyst;Password=DataMining;Initial Catalog=Shopping Cart";
		/// </para>
		/// </example> 
		/// </param>
		/// <returns>
		/// Returns a strongly typed DataSet object containing the transaction data to be analyzed.
		/// </returns>
		/// <value>
		/// A System.Data.DataTable object containing the TransactionID and Transactions columns and data.
		/// </value>
		/// <remarks>
		/// Assumes that a table TransactionsTable with columns TransactionID and Transactions exist in the database.
		/// </remarks>
		public Data GetTransactionsData(string rdbmsConnectionString)
		{
			string selectSQL = "SELECT TransactionID, Transactions FROM TransactionsTable";

			string errorMessage;


			myDatabase = new Data();

			myConnection = new OleDbConnection(rdbmsConnectionString);		
					
			
			try
			{
				myAdapter = new OleDbDataAdapter(selectSQL,myConnection);			

				myAdapter.Fill(myDatabase,"TransactionTable");
			}

			catch (Exception Ex)
			{
				errorMessage = Ex.ToString();
			}			

			return myDatabase;
		}
		
				
		/// <summary>
		/// Retrieves transaction data from a transactions table.
		///  See <see cref="VISUAL_BASIC_DATA_MINING_NET.DataAccessLayer.GetTransactionsData"/>
		/// </summary>
		/// <param name="rdbmsConnectionString">
		/// The connection string used to establish connection to a relational database using ADO.NET.
		///  See <see cref="VISUAL_BASIC_DATA_MINING_NET.DataAccessLayer.GetTransactionsData"/>
		/// </param> 
		/// <param name="dataSource">
		/// A string containing a SQL statement, a table name or the name of a stored procedure.
		/// <para>
		/// The table must have a TransactionID field and a Transactions field.
		/// </para>
		/// <para>
		/// To use a stored procedure named usp_GetTransactions, create the stored procedure in SQL Server using :
		/// <code>
		/// <example>
		/// CREATE  PROCEDURE usp_GetTransactions AS
		/// 
		///	SELECT TransactionID, Transactions FROM TransactionsTable
		///	</example>
		/// </code>
		/// </para>
		/// <para>
		///  The SQL statement used to select transactions data.
		/// <example>
		///  "SELECT TransactionID, Transactions FROM TransactionsTable"
		/// </example>
		/// </para>
		/// </param>
		/// <param name="commandType">
		/// A CommandType enumeration of CommandType.StoredProcedure or CommandType.Text or CommandType.TableDirect.
		/// </param>
		/// <returns>
		/// See
		///  <see cref="VISUAL_BASIC_DATA_MINING_NET.DataAccessLayer.GetTransactionsData"/>
		/// </returns>
		public Data GetTransactionsData(string rdbmsConnectionString, string dataSource, CommandType commandType)
		{
	
			myDatabase = new Data();

			myConnection = new OleDbConnection(rdbmsConnectionString);
	
			myCommand = new OleDbCommand(dataSource,myConnection);
			
			
			if(commandType == CommandType.StoredProcedure)
			{
				myCommand.CommandType = CommandType.StoredProcedure;
			}

			else if(commandType == CommandType.Text)
			{
				myCommand.CommandType = CommandType.Text;
			}

			else if(commandType == CommandType.TableDirect)
			{
				myCommand.CommandType = CommandType.TableDirect;
			}
				
			
			myAdapter = new OleDbDataAdapter();
	
			myAdapter.SelectCommand = myCommand;

			myAdapter.Fill(myDatabase,"TransactionTable");	
						
			
			return myDatabase;
			
		}

		
		/// <summary>
		/// Saves data in memory to a database table.
		/// </summary>
		/// <param name="dataBase">
		/// The in-memory database containing data to be saved to a database.
		/// </param>
		/// <param name="rdbmsConnectionString">
		/// The connection string used to connect to the database.
		/// </param>
		/// <param name="tableName">
		/// The table in the in-memory database containing data used to update a database using the DataAdapter.
		/// </param>
		/// <param name="dataSource">
		/// A string containing a SQL statement, a table name or the name of a stored procedure.
		/// <para>
		/// <param name="commandType">
		/// A CommandType enumeration of CommandType.StoredProcedure or CommandType.Text or CommandType.TableDirect.
		/// </param>
		/// <param name="commandAction">
		/// An action for the DataAdapter to take.
		/// <example>
		/// INSERT, DELETE or UPDATE action on a database.
		/// </example>
		/// </param>
		/// <returns>
		/// A System.Data.DataSet strongly typed object containing data.
		/// </returns>
		public Data SaveDatabaseData(Data dataBase, string rdbmsConnectionString, string tableName, string dataSource,													CommandType	commandType, CommandAction commandAction)
		{
			
			myConnection = new OleDbConnection(rdbmsConnectionString);
	
			myCommand = new OleDbCommand(dataSource,myConnection);
			
			
			if(commandType == CommandType.StoredProcedure)
			{
				myCommand.CommandType = CommandType.StoredProcedure;
			}

			else if(commandType == CommandType.Text)
			{
				myCommand.CommandType = CommandType.Text;
			}

			else if(commandType == CommandType.TableDirect)
			{
				myCommand.CommandType = CommandType.TableDirect;
			}
				
			
			myAdapter = new OleDbDataAdapter();


			if(commandAction == CommandAction.deleteCommand)
			{
				myAdapter.DeleteCommand = myCommand;
			}

			else if(commandAction == CommandAction.insertCommand)
			{
				myAdapter.InsertCommand = myCommand;
			}

			else if(commandAction == CommandAction.updateCommand)
			{
				myAdapter.UpdateCommand = myCommand;
			}	
			

			myAdapter.Update(dataBase, tableName);	
						
			
			return dataBase;

		}
		
		
	}	
	

}