oledbhelper.cs

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

		{
			//pass through the call providing null for the set of OleDbParameters
			return ExecuteReader(connection, commandType, commandText, (OleDbParameter[])null);
		}

		/// <summary>
		/// Execute an OleDbCommand (that returns a resultset) against the specified OleDbConnection 
		/// using the provided parameters.
		/// </summary>
		/// <remarks>
		/// e.g.:  
		///  OleDbDataReader dr = ExecuteReader(conn, CommandType.StoredProcedure, "GetOrders", new OleDbParameter("@prodid", 24));
		/// </remarks>
		/// <param name="connection">a valid OleDbConnection</param>
		/// <param name="commandType">the CommandType (stored procedure, text, etc.)</param>
		/// <param name="commandText">the stored procedure name or PL/SQL command</param>  
		/// <param name="commandParameters">an array of OleDbParamters used to execute the command</param>
		/// <returns>an OleDbDataReader containing the resultset generated by the command</returns>
		public static OleDbDataReader ExecuteReader(OleDbConnection connection, CommandType commandType, string commandText, params OleDbParameter[] commandParameters)
		{
			//pass through the call to the private overload using a null transaction value and an externally owned connection
			return ExecuteReader(connection, (OleDbTransaction)null, commandType, commandText, commandParameters, OleDbConnectionOwnership.External);
		}

		/// <summary>
		/// Execute a stored procedure via an OleDbCommand (that returns a resultset) against the specified OleDbConnection 
		/// using the provided parameter values.  This method will query the database to discover the parameters for the 
		/// stored procedure (the first time each stored procedure is called), 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.:  
		///  OleDbDataReader dr = ExecuteReader(conn, "GetOrders", 24, 36);
		/// </remarks>
		/// <param name="connection">a valid OleDbConnection</param>
		/// <param name="spName">the name of the stored procedure</param>
		/// <param name="parameterValues">an array of objects to be assigned as the input values of the stored procedure</param>
		/// <returns>an OleDbDataReader containing the resultset generated by the command</returns>
		public static OleDbDataReader ExecuteReader(OleDbConnection connection, string spName, params object[] parameterValues)
		{
			//if we got parameter values, we need to figure out where they go
			if ((parameterValues != null) && (parameterValues.Length > 0)) 
			{
				OleDbParameter[] commandParameters = OleDbHelperParameterCache.GetSpParameterSet(connection.ConnectionString, spName);

				AssignParameterValues(commandParameters, parameterValues);

				return ExecuteReader(connection, CommandType.StoredProcedure, spName, commandParameters);
			}
			//otherwise we can just call the SP without params
			else 
			{
				return ExecuteReader(connection, CommandType.StoredProcedure, spName);
			}
		}

		/// <summary>
		/// Execute an OleDbCommand (that returns a resultset and takes no parameters) against the provided OleDbTransaction. 
		/// </summary>
		/// <remarks>
		/// e.g.:  
		///  OleDbDataReader dr = ExecuteReader(trans, CommandType.StoredProcedure, "GetOrders");
		/// </remarks>
		/// <param name="transaction">a valid OleDbTransaction</param>
		/// <param name="commandType">the CommandType (stored procedure, text, etc.)</param>
		/// <param name="commandText">the stored procedure name or PL/SQL command</param>  
		/// <returns>an OleDbDataReader containing the resultset generated by the command</returns>
		public static OleDbDataReader ExecuteReader(OleDbTransaction transaction, CommandType commandType, string commandText)
		{
			//pass through the call providing null for the set of OleDbParameters
			return ExecuteReader(transaction, commandType, commandText, (OleDbParameter[])null);
		}

		/// <summary>
		/// Execute an OleDbCommand (that returns a resultset) against the specified OleDbTransaction
		/// using the provided parameters.
		/// </summary>
		/// <remarks>
		/// e.g.:  
		///   OleDbDataReader dr = ExecuteReader(trans, CommandType.StoredProcedure, "GetOrders", new OleDbParameter("@prodid", 24));
		/// </remarks>
		/// <param name="transaction">a valid OleDbTransaction</param>
		/// <param name="commandType">the CommandType (stored procedure, text, etc.)</param>
		/// <param name="commandText">the stored procedure name or PL/SQL command</param> 
		/// <param name="commandParameters">an array of OleDbParameters used to execute the command</param>
		/// <returns>an OleDbDataReader containing the resultset generated by the command</returns>
		public static OleDbDataReader ExecuteReader(OleDbTransaction transaction, CommandType commandType, string commandText, params OleDbParameter[] commandParameters)
		{
			//pass through to private overload, indicating that the connection is owned by the caller
			return ExecuteReader(transaction.Connection, transaction, commandType, commandText, commandParameters, OleDbConnectionOwnership.External);
		}

		/// <summary>
		/// Execute a stored procedure via an OleDbCommand (that returns a resultset) against the specified
		/// OleDbTransaction using the provided parameter values.  This method will query the database to discover the parameters for the 
		/// stored procedure (the first time each stored procedure is called), 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.:  
		///  OleDbDataReader dr = ExecuteReader(trans, "GetOrders", 24, 36);
		/// </remarks>
		/// <param name="transaction">a valid OleDbTransaction</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 OleDbDataReader containing the resultset generated by the command</returns>
		public static OleDbDataReader ExecuteReader(OleDbTransaction 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)) 
			{
				OleDbParameter[] commandParameters = OleDbHelperParameterCache.GetSpParameterSet(transaction.Connection.ConnectionString, spName);

				AssignParameterValues(commandParameters, parameterValues);

				return ExecuteReader(transaction, CommandType.StoredProcedure, spName, commandParameters);
			}
				//otherwise we can just call the SP without params
			else 
			{
				return ExecuteReader(transaction, CommandType.StoredProcedure, spName);
			}
		}

		#endregion ExecuteReader

		#region ExecuteScalar
		
		/// <summary>
		/// Execute a OleDbCommand (that returns a 1x1 resultset and takes no parameters) against the database specified in 
		/// the connection string. 
		/// </summary>
		/// <remarks>
		/// e.g.:  
		///  int orderCount = (int)ExecuteScalar(connString, CommandType.StoredProcedure, "GetOrderCount");
		/// </remarks>
		/// <param name="connectionString">a valid connection string for a OleDbConnection</param>
		/// <param name="commandType">the CommandType (stored procedure, text, etc.)</param>
		/// <param name="commandText">the stored procedure name or T-OleDb command</param>
		/// <returns>an object containing the value in the 1x1 resultset generated by the command</returns>
		public static object ExecuteScalar(string connectionString, CommandType commandType, string commandText)
		{
			//pass through the call providing null for the set of OleDbParameters
			return ExecuteScalar(connectionString, commandType, commandText, (OleDbParameter[])null);
		}

		/// <summary>
		/// Execute a OleDbCommand (that returns a 1x1 resultset) against the database specified in the connection string 
		/// using the provided parameters.
		/// </summary>
		/// <remarks>
		/// e.g.:  
		///  int orderCount = (int)ExecuteScalar(connString, CommandType.StoredProcedure, "GetOrderCount", new OleDbParameter("@prodid", 24));
		/// </remarks>
		/// <param name="connectionString">a valid connection string for a OleDbConnection</param>
		/// <param name="commandType">the CommandType (stored procedure, text, etc.)</param>
		/// <param name="commandText">the stored procedure name or T-OleDb command</param>
		/// <param name="commandParameters">an array of OleDbParamters 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(string connectionString, CommandType commandType, string commandText, params OleDbParameter[] commandParameters)
		{
			//create & open a OleDbConnection, and dispose of it after we are done.
			using (OleDbConnection cn = new OleDbConnection(connectionString))
			{
				cn.Open();

				//call the overload that takes a connection in place of the connection string
				return ExecuteScalar(cn, commandType, commandText, commandParameters);
			}
		}

		/// <summary>
		/// Execute a stored procedure via a OleDbCommand (that returns a 1x1 resultset) against the database specified in 
		/// the conneciton string using the provided parameter values.  This method will query the database to discover the parameters for the 
		/// stored procedure (the first time each stored procedure is called), 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(connString, "GetOrderCount", 24, 36);
		/// </remarks>
		/// <param name="connectionString">a valid connection string for a OleDbConnection</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(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)
				OleDbParameter[] commandParameters = OleDbHelperParameterCache.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 OleDbParameters
				return ExecuteScalar(connectionString, CommandType.StoredProcedure, spName, commandParameters);
			}
				//otherwise we can just call the SP without params
			else 
			{
				return ExecuteScalar(connectionString, CommandType.StoredProcedure, spName);
			}
		}

		/// <summary>
		/// Execute a OleDbCommand (that returns a 1x1 resultset and takes no parameters) against the provided OleDbConnection. 
		/// </summary>
		/// <remarks>
		/// e.g.:  
		///  int orderCount = (int)ExecuteScalar(conn, CommandType.StoredProcedure, "GetOrderCount");
		/// </remarks>
		/// <param name="connection">a valid OleDbConnection</param>
		/// <param name="commandType">the CommandType (stored procedure, text, etc.)</param>
		/// <param name="commandText">the stored procedure name or T-OleDb command</param>
		/// <returns>an object containing the value in the 1x1 resultset generated by the command</returns>
		public static object ExecuteScalar(OleDbConnection connection, CommandType commandType, string commandText)
		{
			//pass through the call providing null for the set of OleDbParameters
			return ExecuteScalar(connection, commandType, commandText, (OleDbParameter[])null);
		}

		/// <summary>
		/// Execute a OleDbCommand (that returns a 1x1 resultset) against the specified OleDbConnection 
		/// using the provided parameters.
		/// </summary>
		/// <remarks>
		/// e.g.:  
		///  int orderCount = (int)ExecuteScalar(conn, CommandType.StoredProcedure, "GetOrderCount", new OleDbParameter("@prodid", 24));
		/// </remarks>
		/// <param name="connection">a valid OleDbConnection</param>
		/// <param name="commandType">the CommandType (stored procedure, text, etc.)</param>
		/// <param name="commandText">the stored procedure name or T-OleDb command</param>
		/// <param name="commandParameters">an array of OleDbParamters 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(OleDbConnection connection, CommandType commandType, string commandText, params OleDbParameter[] commandParameters)
		{
			//create a command and prepare it for execution
			OleDbCommand cmd = new OleDbCommand();
			PrepareCommand(cmd, connection, (OleDbTransaction)null, commandType, commandText, commandParameters);
			
			//execute the command & return the results
			return cmd.ExecuteScalar();
		}

		/// <summary>
		/// Execute a stored procedure via a OleDbCommand (that returns a 1x1 resultset) against the specified OleDbConnection 
		/// using the provided parameter values.  This method will query the database to discover the parameters for the 
		/// stored procedure (the first time each stored procedure is called), 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.