include/AbsSqlConnection.h

   1 /***************************************************************************
   2  *                                                                         *
   3  *    Copyright (C) Lakshya Solutions Ltd. All rights reserved.            *
   4  *                                                                         *
   5  ***************************************************************************/
   6 #ifndef ABSSQLCONNECTION_H
   7 #define ABSSQLCONNECTION_H
   8 #include<os.h>
   9 #include<ErrorType.h>
  10 #include<Session.h>
  11 #include<Util.h>
  12 class Connection;
  13 class CachedTable{
  14     public:
  15     char tableName[IDENTIFIER_LENGTH];
  16     CachedTable() { tableName[0] = '\0'; }
  17 };
  18
  19 enum TransSyncMode {
  20     OSYNC=1,
  21     ASYNC=2,
  22     OASYNC=3
  23 };
  24
  25 enum TableSyncMode {
  26     TABLE_OSYNC=1,
  27     TABLE_ASYNC=2
  28 };
  29 /**
  30 * @class AbsSqlConnection
  31 *
  32 * \brief Represents a database connection to sql engine.
  33 *
  34 * It represents the database connection to the sql engine.\n
  35 * All database operations shall be done within the context of the connection.\n
  36 * Application should first create object of this class to accessing the database\n
  37 * through SQL Engine.
  38 * Each connection has only one active transaction at any given point of time, all \n
  39 * operations which happen using this connection object will be done as part of that \n
  40 * transaction.\n
  41 * \n
  42 *  Note: \n
  43 *  SERIALIZABLE isolation level is not supported. \n
  44 */
  45 class AbsSqlConnection
  46 {
  47     protected:
  48     AbsSqlConnection *innerConn;
  49     public:
  50     void setInnerConnection(AbsSqlConnection *conn) { innerConn = conn; }
  51     AbsSqlConnection* getInnerConnection() { return innerConn; }
  52     virtual Connection& getConnObject() =0;
  53
  54     /** opens connection to the sql engine
  55     *   @param user username for authentication
  56     *   @param pass password for authentication
  57     *   @return DbRetVal
  58     */
  59     virtual DbRetVal connect (char *user, char * pass) =0;
  60
  61     /** closes connection to the sql engine and releases all the resources
  62     *   @return DbRetVal
  63     */
  64     virtual DbRetVal disconnect () = 0;
  65
  66     /** Commits active transaction. \n
  67     *   It makes all the changes made in the current transaction permanent and \n
  68     *   it also releases the locks held by the current transaction.\n
  69     *   After a transaction commits, application is required to start another \n
  70     *   transaction for further database operations.\n
  71     *   @return DbRetVal
  72     */
  73     virtual DbRetVal commit() = 0;
  74
  75     /** Aborts the active transaction.\n
  76     *   undo all the changes made in the current transaction and it also \n
  77     *   releases the locks held by the current transaction.\n
  78     *   After a transaction rollback, application is required to start another \n
  79     *   transaction for further database operations.\n
  80     *   @return DbRetVal
  81     */
  82     virtual DbRetVal rollback() = 0;
  83
  84     /** Starts a new transaction.\n
  85     *   The previous transaction should be either committed or rollback \n
  86     *   before beginTrans is called. \n
  87     *   Applications are required to start transaction before they attempt any \n
  88     *   database operation.\n
  89     *   @param isoLevel isolation level. Default is read committed.
  90     *   @return DbRetVal
  91     */
  92     virtual DbRetVal beginTrans (IsolationLevel isoLevel = READ_COMMITTED,
  93                                  TransSyncMode mode = OSYNC) = 0;
  94     virtual ~AbsSqlConnection()
  95     {
  96         if (innerConn) { delete innerConn; innerConn = NULL; }
  97     }
  98     virtual void display()
  99     {
 100         if (innerConn)  innerConn->display();
 101     }
 102 };
 103
 104 #endif