src/DAL/SelectionMask.h

   1 /***************************************************************************
   2  *   Copyright (C) 2008 by Sverre Rabbelier                                *
   3  *   sverre@rabbelier.nl                                                   *
   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 3 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 #pragma once
  21
  22 /**
  23  * @file SelectionMask.h
  24  * This file contains the SelectionMask class.
  25  *
  26  * @see SelectionMask
  27  */
  28
  29 #include "Types.h"
  30
  31 typedef std::vector<KeysPtr> KeysVector; /**< The type of multiple key bucket pointers. */
  32
  33 /**
  34  * This class is meant to be used to filter queries to the database.
  35  *
  36  * When used in conjunction with <code>selectMulti</code> it allows selecting specific row's from the database from a native table.
  37  * Through <code>addJoin</code> additional foreign tables may be joined into the query.
  38  * With <code>addField</code> a restriction for that specific field may be applied.
  39  * Finally the result of the query may be retreived with <code>getResult</code>.
  40  *
  41  * @see SqliteMgr::selectMulti
  42  * @see addJoin
  43  * @see addField
  44  * @see getResult
  45  */
  46 class SelectionMask
  47 {
  48         public:
  49                 /** Constructs a SelectionMask for this specific table. */
  50                 SelectionMask(TableImplPtr table);
  51
  52                 /** Destructor, a noop. */
  53                 ~SelectionMask();
  54
  55                 /** Returns the native table this SelectionMask is for. */
  56                 TableImplPtr getTable() const;
  57
  58                 /** Adds a field restriction, the row's returned will all have the specified value. */
  59                 void addField(ValuePtr value);
  60
  61                 /** Adds a field restriction, the row's returned will all have the specified value. */
  62                 void addField(FieldImplPtr field, cstring value);
  63
  64                 /** Adds a field restriction, the row's returned will all have the specified value. */
  65                 void addField(FieldImplPtr field, value_type value);
  66
  67                 /**
  68                  * Adds a join to the specified table from the native table using the specified native and foreign keys.
  69                  * When creating a join from an already joined table, specify that table.
  70                  *
  71                  * @param joinTable The table to join on.
  72                  * @param nativeKey The native key to use in the join, this key should belong to the native table.
  73                  * @param foreignKey The foreign key to use in the join, this key should belong to the specified foreign table.
  74                  *
  75                  * @see addJoin
  76                  */
  77                 void addJoin(TableImplPtr joinTable, KeyImplPtr nativeKey, KeyImplPtr foreignKey);
  78
  79                 /**
  80                  * Adds a join to the specified table from the specified table using the specified native and foreign keys.
  81                  *
  82                  * @param nativeTable The table to join from, this table should have been added with addJoin before.
  83                  * @param joinTable The table to join on.
  84                  * @param nativeKey The native key to use in the join, this key should belong to the native table.
  85                  * @param foreignKey The foreign key to use in the join, this key should belong to the specified foreign table.
  86                  *
  87                  * @see addJoin
  88                  */
  89                 void addJoin(TableImplPtr nativeTable, TableImplPtr joinTable, KeyImplPtr nativeKey, KeyImplPtr foreignKey);
  90
  91                 /** Adds the specified join, this join should be from a table that is either the native table or joined previously. */
  92                 void addJoin(JoinPtr join);
  93
  94
  95                 /** Bind the specified statement's values. */
  96                 void bindSelectMulti(sqlite3* db, sqlite3_stmt* statement) const;
  97
  98                 /** Parse a row from the statement and store it. */
  99                 void parseRow(sqlite3_stmt* statement);
 100
 101                 /** Parse a count from the statement and store it. */
 102                 void parseCount(sqlite3_stmt* statement);
 103
 104
 105                 /** Returns the size of the fields restricted on. */
 106                 size_t size() { return m_restrictions.size(); }
 107
 108                 /** Returns an iterator to the first restriction fields. */
 109                 Strings::const_iterator begin() { return m_restrictions.begin(); }
 110
 111                 /** Returns the 'end' iterator of the restriction fields. */
 112                 Strings::const_iterator end() { return m_restrictions.end(); }
 113
 114
 115                 /** Returns the size of the joins. */
 116                 size_t joinssize() { return m_joins.size(); }
 117
 118                 /** Returns an iterator to the first join. */
 119                 Joins::const_iterator joinsbegin() { return m_joins.begin(); }
 120
 121                 /** Returns the 'end' iterator of the joins. */
 122                 Joins::const_iterator joinsend() { return m_joins.end(); }
 123
 124
 125                 /** Returns the result of the lookup. */
 126                 SavableManagersPtr getResult() { return m_result; }
 127
 128                 /** Returns the row count. */
 129                 size_t getCount() { return m_count; }
 130
 131         private:
 132                 /** Returns wether the specified table has been joined (or is equal to the native table) or not. */
 133                 bool isReachableTable(TableImplPtr table);
 134
 135                 TableImplPtr m_nativeTable; /**< The native table for this selection. */
 136                 ValuesPtr m_values; /**< The value restrictions for this selection. */
 137                 TableImplVector m_foreignTables; /**< The foreign tables for this selection. */
 138                 Joins m_joins; /**< The joins for this selection. */
 139                 Strings m_restrictions; /**< The fields this selection restricts. */
 140
 141                 SavableManagersPtr m_result; /**< The result of the selection. */
 142                 size_t m_count; /**< The amount of entries that matches. */
 143 };