sqlite/sqlitealter.cpp

/* This file is part of the KDE project
   Copyright (C) 2006 Jaroslaw Staniek <js@iidea.pl>
 
   This program is free software; you can redistribute it and/or
   modify it under the terms of the GNU Library General Public
   License as published by the Free Software Foundation; either
   version 2 of the License, or (at your option) any later version.
 
   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   Library General Public License for more details.
 
   You should have received a copy of the GNU Library General Public License
   along with this program; see the file COPYING.  If not, write to
   the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
 * Boston, MA 02110-1301, USA.
*/
 
// ** bits of SQLiteConnection related to table altering **
 
#include "sqliteconnection.h"
#include <kexidb/utils.h>
 
#include <kstaticdeleter.h>
 
#include <tqmap.h>
 
using namespace KexiDB;
 
enum SQLiteTypeAffinity { //as defined here: 2.1 Determination Of Column Affinity (http://sqlite.org/datatype3.html)
    NoAffinity = 0, IntAffinity = 1, TextAffinity = 2, BLOBAffinity = 3
};

static KStaticDeleter< TQMap<int,int> > KexiDB_SQLite_affinityForType_deleter;
TQMap<int,int> *KexiDB_SQLite_affinityForType = 0;

static SQLiteTypeAffinity affinityForType(Field::Type type)
{
    if (!KexiDB_SQLite_affinityForType) {
        KexiDB_SQLite_affinityForType_deleter.setObject( KexiDB_SQLite_affinityForType, new TQMap<int,int>() );
        KexiDB_SQLite_affinityForType->insert(Field::Byte, IntAffinity);
        KexiDB_SQLite_affinityForType->insert(Field::ShortInteger, IntAffinity);
        KexiDB_SQLite_affinityForType->insert(Field::Integer, IntAffinity);
        KexiDB_SQLite_affinityForType->insert(Field::BigInteger, IntAffinity);
        KexiDB_SQLite_affinityForType->insert(Field::Boolean, IntAffinity);
        KexiDB_SQLite_affinityForType->insert(Field::Date, TextAffinity);
        KexiDB_SQLite_affinityForType->insert(Field::DateTime, TextAffinity);
        KexiDB_SQLite_affinityForType->insert(Field::Time, TextAffinity);
        KexiDB_SQLite_affinityForType->insert(Field::Float, IntAffinity);
        KexiDB_SQLite_affinityForType->insert(Field::Double, IntAffinity);
        KexiDB_SQLite_affinityForType->insert(Field::Text, TextAffinity);
        KexiDB_SQLite_affinityForType->insert(Field::LongText, TextAffinity);
        KexiDB_SQLite_affinityForType->insert(Field::BLOB, BLOBAffinity);
    }
    return static_cast<SQLiteTypeAffinity>((*KexiDB_SQLite_affinityForType)[(int)type]);
}
 
tristate SQLiteConnection::drv_changeFieldProperty(TableSchema &table, Field& field, 
    const TQString& propertyName, const TQVariant& value)
{
/*  if (propertyName=="name") {
        
    }*/
    if (propertyName=="type") {
        bool ok;
        Field::Type type = KexiDB::intToFieldType( value.toUInt(&ok) );
        if (!ok || Field::InvalidType == type) {
            return false;
        }
        return changeFieldType(table, field, type);
    }
    // not found
    return cancelled;
}

tristate SQLiteConnection::changeFieldType(TableSchema &table, Field& field, 
    Field::Type type)
{
    Q_UNUSED(table);
    const Field::Type oldType = field.type();
    const SQLiteTypeAffinity oldAffinity = affinityForType(oldType);
    const SQLiteTypeAffinity newAffinity = affinityForType(type);
    if (oldAffinity!=newAffinity) {
        //type affinity will be changed
    }
 
    return cancelled;
}