include/SqlConnection.h

   1 /***************************************************************************
   2  *   Copyright (C) 2007 by Prabakaran Thirumalai   *
   3  *   praba_tuty@yahoo.com   *
   4  *                                                                         *
   5  *   This program is free software; you can redistribute it and/or modify  *
   6  *   it under the terms of the GNU General Public License as published by  *
   7  *   the Free Software Foundation; either version 2 of the License, or     *
   8  *   (at your option) any later version.                                   *
   9  *                                                                         *
  10  *   This program is distributed in the hope that it will be useful,       *
  11  *   but WITHOUT ANY WARRANTY; without even the implied warranty of        *
  12  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         *
  13  *   GNU General Public License for more details.                          *
  14  *                                                                         *
  15  *   You should have received a copy of the GNU General Public License     *
  16  *   along with this program; if not, write to the                         *
  17  *   Free Software Foundation, Inc.,                                       *
  18  *   59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.             *
  19  ***************************************************************************/
  20 #ifndef SQLCONNECTION_H
  21 #define SQLCONNECTION_H
  22 #include<CSql.h>
  23
  24 /**
  25 * @class SqlConnection
  26 *
  27 * @brief Represents a database connection to sql engine.
  28 * All database operations shall be done within the context of the connection. <br>
  29 * Application should first create object of this class for accessing the database.<br/>
  30 * Each connection has only one active transaction at any given point of time, all <br/>
  31 * operations which happen using this connection object will be done as part of that <br/>
  32 * transaction.<br/>
  33 * <br/>
  34 * Functionality: <br/>
  35 *     1.Connection Management (connect and disconnect) <br/>
  36 *     2.Transaction Management (start, commit, abort) <br/>
  37 * <br/>
  38 *  Note: <br/>
  39 *  SERIALIZABLE isolation level is not supported.
  40 * @author Prabakaran Thirumalai
  41 */
  42 class SqlConnection
  43 {
  44     Connection conn;
  45     public:
  46
  47     /** opens connection to the sql engine
  48     *   @param user username for authentication
  49     *   @param pass password for authentication
  50     *   @return DbRetVal
  51     */
  52     DbRetVal connect (char *user, char * pass)
  53         { return conn.open(user, pass); }
  54
  55     /** closes connection to the database and releases all the resources
  56     *   @return DbRetVal
  57     */
  58     DbRetVal disconnect () { return conn.close(); }
  59
  60     /** Commits active transaction.
  61     *   It makes all the changes made in the current transaction permanent and <br/>
  62     *   it also releases the locks held by the current transaction.<br/>
  63     *   After a transaction commits, application is required to start another <br/>
  64     *   transaction for further database operations.
  65     *   @return DbRetVal
  66     */
  67     DbRetVal commit() { return conn.commit(); }
  68
  69     /** Aborts the active transaction.
  70     *   undo all the changes made in the current transaction and it also <br/>
  71     *   releases the locks held by the current transaction.<br/>
  72     *   After a transaction rollback, application is required to start another <br/>
  73     *   transaction for further database operations.
  74     *   @return DbRetVal
  75     */
  76     DbRetVal rollback() { return conn.rollback(); }
  77
  78     /** Starts a transaction.
  79     *   The previous transaction should be either committed or rollback <br/>
  80     *   before beginTrans is called. <br/>
  81     *   Applications are required to start transaction before they attempt any <br>
  82     *   database operation.
  83     *   @param isoLevel isolation level. Default is read committed.
  84     *   @return DbRetVal
  85     */
  86     DbRetVal beginTrans (IsolationLevel isoLevel = READ_COMMITTED)
  87         { return conn.startTransaction(isoLevel); }
  88
  89     Connection& getConnObject(){  return conn; }
  90 };
  91
  92 #endif