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>
		/// <remarks>
		/// e.g.:  
		///  int orderCount = (int)ExecuteScalar(conn, trans, CommandType.StoredProcedure, "GetOrderCount");
		/// </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>an object containing the value in the 1x1 resultset generated by the command</returns>
		public static object ExecuteScalar(SqlConnection connection, SqlTransaction transaction, CommandType commandType, string commandText)
		{
			//pass through the call providing null for the set of SqlParameters
			return ExecuteScalar(connection, transaction, commandType, commandText, (SqlParameter[])null);
		}

		/// <summary>
		/// Execute a SqlCommand (that returns a 1x1 resultset) against the specified SqlConnection and SqlTransaction
		/// using the provided parameters.
		/// </summary>
		/// <remarks>
		/// e.g.:  
		///  int orderCount = (int)ExecuteScalar(conn, trans, CommandType.StoredProcedure, "GetOrderCount", 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>an object containing the value in the 1x1 resultset generated by the command</returns>
		public static object ExecuteScalar(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);
			
			//execute the command & return the results
			return cmd.ExecuteScalar();

		}

		/// <summary>
		/// Execute a stored procedure via a SqlCommand (that returns a 1x1 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.:  
		///  int orderCount = (int)ExecuteScalar(conn, trans, "GetOrderCount", 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>an object containing the value in the 1x1 resultset generated by the command</returns>
		public static object ExecuteScalar(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 ExecuteScalar(connection, transaction, CommandType.StoredProcedure, spName, commandParameters);
			}
			//otherwise we can just call the SP without params
			else 
			{
				return ExecuteScalar(connection, transaction, CommandType.StoredProcedure, spName);
			}
		}

		#endregion ExecuteScalar	

		#region ExecuteXmlReader

		/// <summary>
		/// Execute a SqlCommand (that returns a resultset and takes no parameters) against the provided SqlConnection. 
		/// </summary>
		/// <remarks>
		/// e.g.:  
		///  XmlReader r = ExecuteXmlReader(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 using "FOR XML AUTO"</param>
		/// <returns>an XmlReader containing the resultset generated by the command</returns>
		public static XmlReader ExecuteXmlReader(SqlConnection connection, CommandType commandType, string commandText)
		{
			//pass through the call using a null transaction value
			return ExecuteXmlReader(connection, null, commandType, commandText);
		}

		/// <summary>
		/// Execute a SqlCommand (that returns a resultset) against the specified SqlConnection 
		/// using the provided parameters.
		/// </summary>
		/// <remarks>
		/// e.g.:  
		///  XmlReader r = ExecuteXmlReader(conn, CommandType.StoredProcedure, "GetOrders", new SqlParameter("@prodid", 24));
		/// </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 using "FOR XML AUTO"</param>
		/// <param name="commandParameters">an array of SqlParamters used to execute the command</param>
		/// <returns>an XmlReader containing the resultset generated by the command</returns>
		public static XmlReader ExecuteXmlReader(SqlConnection connection, CommandType commandType, string commandText, params SqlParameter[] commandParameters)
		{
			//pass through the call using a null transaction value
			return ExecuteXmlReader(connection, null, commandType, commandText, commandParameters);
		}

		/// <summary>
		/// Execute a stored procedure via a SqlCommand (that returns a resultset) against the specified SqlConnection 
		/// 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.:  
		///  XmlReader r = ExecuteXmlReader(conn, "GetOrders", 24, 36);
		/// </remarks>
		/// <param name="connection">a valid SqlConnection</param>
		/// <param name="spName">the name of the stored prcedure using "FOR XML AUTO"</param>
		/// <param name="parameterValues">an array of objects to be assigned as the input values of the stored procedure</param>
		/// <returns>an XmlReader containing the resultset generated by the command</returns>
		public static XmlReader ExecuteXmlReader(SqlConnection connection, string spName, params object[] parameterValues)
		{
			//pass through the call using a null transaction value
			return ExecuteXmlReader(connection, null, spName, parameterValues);
		}

		//these three method overloads currently take both connection and transaction.  In post-beta2 builds, only 
		//transaction will need to be passed in, and the .Connection property will be available from that transaction

		/// <summary>
		/// Execute a SqlCommand (that returns a resultset and takes no parameters) against the provided SqlConnection
		/// and SqlTransaction. 
		/// </summary>
		/// <remarks>
		/// e.g.:  
		///  XmlReader r = ExecuteXmlReader(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 using "FOR XML AUTO"</param>
		/// <returns>an XmlReader containing the resultset generated by the command</returns>
		public static XmlReader ExecuteXmlReader(SqlConnection connection, SqlTransaction transaction, CommandType commandType, string commandText)
		{
			//pass through the call providing null for the set of SqlParameters
			return ExecuteXmlReader(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.:  
		///  XmlReader r = ExecuteXmlReader(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 using "FOR XML AUTO"</param>
		/// <param name="commandParameters">an array of SqlParamters used to execute the command</param>
		/// <returns>an XmlReader containing the resultset generated by the command</returns>
		public static XmlReader ExecuteXmlReader(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
			return cmd.ExecuteXmlReader();
		}

		/// <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.:  
		///  XmlReader r = ExecuteXmlReader(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 XmlReader ExecuteXmlReader(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 ExecuteXmlReader(connection, transaction, CommandType.StoredProcedure, spName, commandParameters);
			}
			//otherwise we can just call the SP without params
			else 
			{
				return ExecuteXmlReader(connection, transaction, CommandType.StoredProcedure, spName);
			}
		}


		#endregion ExecuteXmlReader
	}

	/// <summary>
	/// SqlHelperParameterCache provides functions to leverage a static cache of procedure parameters, and the
	/// ability to discover parameters for stored procedures at run-time.
	/// </summary>
	public sealed class SqlHelperParameterCache
	{
		#region private methods, variables, and constructors

		//Since this class provides only static methods, make the default constructor private to prevent 
		//instances from being created with "new SqlHelperParameterCache()".
		private SqlHelperParameterCache() {}

		//these hashtables are used to map the sp_procedure_params_rowset resultset to the SqlCommand property enum values
		private static Hashtable paramCache = Hashtable.Synchronized(new Hashtable());
		private static Hashtable paramTypes = Hashtable.Synchronized(new Hashtable());
		private static Hashtable paramDirections = Hashtable.Synchronized(new Hashtable());

		/// <summary>
		/// resolve at run-time the appropriate set of SqlParameters for a stored procedure
		/// </summary>
		/// <param name="connectionString">a valid connection string for a SqlConnection</param>
		/// <param name="spName">the name of the stored prcedure</param>
		/// <param name="includeReturnValueParameter">weather or not to onclude ther return value parameter</param>
		/// <returns></returns>
		private static SqlParameter[] DiscoverSpParameterSet(string connectionString, string spName, bool includeReturnValueParameter)
		{
			DataTable paramDescriptions = new DataTable("paramDescriptions");
			using (SqlConnection cn = new SqlConnection(connectionString))