using System; using System.Configuration; using System.Data; using System.Data.OracleClient; using System.Collections; using System.Data.OleDb; namespace DBUtility { /// <summary> /// A helper class used to execute queries against an Oracle database /// </summary> public abstract class OracleHelper { // Read the connection strings from the configuration file public static readonly string connectionString = ConfigurationManager.AppSettings["OrdersDAL"]; //Create a hashtable for the parameter cached private static Hashtable parmCache = Hashtable.Synchronized(new Hashtable()); /// <summary> /// Execute a database query which does not include a select /// </summary> /// <param name="connString">Connection string to database</param> /// <param name="cmdType">Command type either stored procedure or SQL</param> /// <param name="cmdText">Acutall SQL Command</param> /// <param name="commandParameters">Parameters to bind to the command</param> /// <returns></returns> public static int ExecuteNonQuery(string connectionString, CommandType cmdType, string cmdText, params OleDbParameter[] commandParameters) { // Create a new Oracle command OleDbCommand cmd = new OleDbCommand(); //Create a connection using (OleDbConnection connection = new OleDbConnection(connectionString)) { //Prepare the command PrepareCommand(cmd, connection, null, cmdType, cmdText, commandParameters); //Execute the command int val = cmd.ExecuteNonQuery(); cmd.Parameters.Clear(); return val; } } /// <summary> /// Execute an OleDbCommand (that returns no resultset) against an existing database transaction /// using the provided parameters. /// </summary> /// <remarks> /// e.g.: /// int result = ExecuteNonQuery(trans, CommandType.StoredProcedure, "PublishOrders", new OleDbParameter(":prodid", 24)); /// </remarks> /// <param name="trans">an existing database transaction</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 OracleParamters used to execute the command</param> /// <returns>an int representing the number of rows affected by the command</returns> public static int ExecuteNonQuery(OleDbTransaction trans, CommandType cmdType, string cmdText, params OleDbParameter[] commandParameters) { OleDbCommand cmd = new OleDbCommand(); PrepareCommand(cmd, trans.Connection, trans, cmdType, cmdText, commandParameters); int val = cmd.ExecuteNonQuery(); cmd.Parameters.Clear(); return val; } /// <summary> /// Execute an OleDbCommand (that returns no resultset) against an existing database connection /// using the provided parameters. /// </summary> /// <remarks> /// e.g.: /// int result = ExecuteNonQuery(connString, CommandType.StoredProcedure, "PublishOrders", new OleDbParameter(":prodid", 24)); /// </remarks> /// <param name="conn">an existing database connection</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 OracleParamters used to execute the command</param> /// <returns>an int representing the number of rows affected by the command</returns> public static int ExecuteNonQuery(OleDbConnection connection, CommandType cmdType, string cmdText, params OleDbParameter[] commandParameters) { OleDbCommand cmd = new OleDbCommand(); PrepareCommand(cmd, connection, null, cmdType, cmdText, commandParameters); int val = cmd.ExecuteNonQuery(); cmd.Parameters.Clear(); return val; } /// <summary> /// Execute a select query that will return a result set /// </summary> /// <param name="connString">Connection string</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 OracleParamters used to execute the command</param> /// <returns></returns> public static OleDbDataReader ExecuteReader(string connectionString, CommandType cmdType, string cmdText, params OleDbParameter[] commandParameters) { //Create the command and connection OleDbCommand cmd = new OleDbCommand(); OleDbConnection conn = new OleDbConnection(connectionString); try { //Prepare the command to execute PrepareCommand(cmd, conn, null, cmdType, cmdText, commandParameters); //Execute the query, stating that the connection should close when the resulting datareader has been read OleDbDataReader rdr = cmd.ExecuteReader(CommandBehavior.CloseConnection); cmd.Parameters.Clear(); return rdr; } catch { //If an error occurs close the connection as the reader will not be used and we expect it to close the connection conn.Close(); throw; } } /// <summary> /// Execute an OleDbCommand that returns the first column of the first record against the database specified in the connection string /// using the provided parameters. /// </summary> /// <remarks> /// e.g.: /// Object obj = ExecuteScalar(connString, CommandType.StoredProcedure, "PublishOrders", new OleDbParameter(":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 PL/SQL command</param> /// <param name="commandParameters">an array of OracleParamters used to execute the command</param> /// <returns>An object that should be converted to the expected type using Convert.To{Type}</returns> public static object ExecuteScalar(string connectionString, CommandType cmdType, string cmdText, params OleDbParameter[] commandParameters) { OleDbCommand cmd = new OleDbCommand(); using (OleDbConnection conn = new OleDbConnection(connectionString)) { PrepareCommand(cmd, conn, null, cmdType, cmdText, commandParameters); object val = cmd.ExecuteScalar(); cmd.Parameters.Clear(); return val; } } /// <summary> /// Execute a OleDbCommand (that returns a 1x1 resultset) against the specified SqlTransaction /// using the provided parameters. /// </summary> /// <param name="transaction">A valid SqlTransaction</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 OracleParamters 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(OleDbTransaction transaction, CommandType commandType, string commandText, params OleDbParameter[] commandParameters) { if (transaction == null) throw new ArgumentNullException("transaction"); if (transaction != null && transaction.Connection == null) throw new ArgumentException("The transaction was rollbacked or commited, please provide an open transaction.", "transaction"); // Create a command and prepare it for execution OleDbCommand cmd = new OleDbCommand(); PrepareCommand(cmd, transaction.Connection, transaction, commandType, commandText, commandParameters); // Execute the command & return the results object retval = cmd.ExecuteScalar(); // Detach the SqlParameters from the command object, so they can be used again cmd.Parameters.Clear(); return retval; } /// <summary> /// Execute an OleDbCommand that returns the first column of the first record against an existing database connection /// using the provided parameters. /// </summary> /// <remarks> /// e.g.: /// Object obj = ExecuteScalar(conn, CommandType.StoredProcedure, "PublishOrders", new OleDbParameter(":prodid", 24)); /// </remarks> /// <param name="conn">an existing database connection</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 OracleParamters used to execute the command</param> /// <returns>An object that should be converted to the expected type using Convert.To{Type}</returns> public static object ExecuteScalar(OleDbConnection connectionString, CommandType cmdType, string cmdText, params OleDbParameter[] commandParameters) { OleDbCommand cmd = new OleDbCommand(); PrepareCommand(cmd, connectionString, null, cmdType, cmdText, commandParameters); object val = cmd.ExecuteScalar(); cmd.Parameters.Clear(); return val; } /// <summary> /// Add a set of parameters to the cached /// </summary> /// <param name="cacheKey">Key value to look up the parameters</param> /// <param name="commandParameters">Actual parameters to cached</param> public static void CacheParameters(string cacheKey, params OleDbParameter[] commandParameters) { parmCache[cacheKey] = commandParameters; } /// <summary> /// Fetch parameters from the cache /// </summary> /// <param name="cacheKey">Key to look up the parameters</param> /// <returns></returns> public static OleDbParameter [] GetCachedParameters(string cacheKey) { OleDbParameter[] cachedParms = (OleDbParameter[])parmCache[cacheKey]; if (cachedParms == null) return null; // If the parameters are in the cache OleDbParameter[] clonedParms = new OleDbParameter[cachedParms.Length]; // return a copy of the parameters for (int i = 0, j = cachedParms.Length; i < j; i++) clonedParms[i] = (OleDbParameter)((ICloneable)cachedParms[i]).Clone(); return clonedParms; } /// <summary> /// Internal function to prepare a command for execution by the database /// </summary> /// <param name="cmd">Existing command object</param> /// <param name="conn">Database connection object</param> /// <param name="trans">Optional transaction object</param> /// <param name="cmdType">Command type, e.g. stored procedure</param> /// <param name="cmdText">Command test</param> /// <param name="commandParameters">Parameters for the command</param> private static void PrepareCommand(OleDbCommand cmd, OleDbConnection conn, OleDbTransaction trans, CommandType cmdType, string cmdText, OleDbParameter[] commandParameters) { //Open the connection if required if (conn.State != ConnectionState.Open) conn.Open(); //Set up the command cmd.Connection = conn; cmd.CommandText = cmdText; cmd.CommandType = cmdType; //Bind it to the transaction if it exists if (trans != null) cmd.Transaction = trans; // Bind the parameters passed in if (commandParameters != null) { foreach (OleDbParameter parm in commandParameters) cmd.Parameters.Add(parm); } } /// <summary> /// Converter to use boolean data type with Oracle /// </summary> /// <param name="value">Value to convert</param> /// <returns></returns> public static string OraBit(bool value) { if (value) return "Y"; else return "N"; } /// <summary> /// Converter to use boolean data type with Oracle /// </summary> /// <param name="value">Value to convert</param> /// <returns></returns> public static bool OraBool(string value) { if (value.Equals("Y")) return true; else return false; } } }