diff --git a/src/database.cpp b/src/database.cpp
index b923e34..5420c42 100644
--- a/src/database.cpp
+++ b/src/database.cpp
@@ -48,6 +48,7 @@
 NUT_BEGIN_NAMESPACE
 
 int DatabasePrivate::lastId = 0;
+QMap<QString, DatabaseModel> DatabasePrivate::allTableMaps;
 
 DatabasePrivate::DatabasePrivate(Database *parent) : q_ptr(parent)
 {
@@ -56,8 +57,8 @@ DatabasePrivate::DatabasePrivate(Database *parent) : q_ptr(parent)
 bool DatabasePrivate::open(bool update)
 {
     Q_Q(Database);
-    if (update)
-        getCurrectScheema();
+//    if (update)
+    bool isNew = getCurrectScheema();
 
     connectionName = q->metaObject()->className()
                      + QString::number(DatabasePrivate::lastId);
@@ -98,7 +99,7 @@ bool DatabasePrivate::open(bool update)
         return false;
     }
 
-    if(update)
+    if(isNew)
         return updateDatabase();
     else
         return true;
@@ -124,7 +125,6 @@ bool DatabasePrivate::updateDatabase()
     QStringList sql = sqlGenertor->diff(last, current);
     db.transaction();
     foreach (QString s, sql) {
-        qDebug() <<"cmd="<<s;
         db.exec(s);
 
         if (db.lastError().type() != QSqlError::NoError)
@@ -158,9 +158,14 @@ bool DatabasePrivate::updateDatabase()
     return ok;
 }
 
-void DatabasePrivate::getCurrectScheema()
+bool DatabasePrivate::getCurrectScheema()
 {
     Q_Q(Database);
+    if (allTableMaps.contains(q->metaObject()->className())) {
+        currentModel = allTableMaps[q->metaObject()->className()];
+        return false;
+    }
+
     tables.clear();
 
     // TODO: change logs must not be in model
@@ -201,7 +206,6 @@ void DatabasePrivate::getCurrectScheema()
         QMetaProperty tableProperty = q->metaObject()->property(i);
         int typeId = QMetaType::type(tableProperty.typeName());
 
-        qDebug() << tables.values().contains(tableProperty.name()) << typeId;
         if (tables.values().contains(tableProperty.name())
             && typeId >= QVariant::UserType) {
             TableModel *sch = new TableModel(typeId, tableProperty.name());
@@ -212,6 +216,9 @@ void DatabasePrivate::getCurrectScheema()
     foreach (TableModel *sch, currentModel)
         foreach (RelationModel *fk, sch->foregionKeys())
             fk->table = currentModel.modelByClass(fk->className);
+
+    allTableMaps.insert(q->metaObject()->className(), currentModel);
+    return true;
 }
 
 DatabaseModel DatabasePrivate::getLastScheema()
@@ -251,7 +258,6 @@ DatabaseModel DatabasePrivate::getLastScheema()
     //            ret.append(sch);
     //        }
     //    }
-    // qDebug() << "ret=" <<ret;
     //    return ret;
 }
 
@@ -385,7 +391,7 @@ DatabaseModel Database::model() const
 QString Database::tableName(QString className)
 {
     Q_D(Database);
-    return d->tables[className];
+    return model().modelByClass(className)->name();
 }
 
 void Database::setDatabaseName(QString databaseName)
@@ -494,8 +500,9 @@ QSqlQuery Database::exec(QString sql)
 
     QSqlQuery q = d->db.exec(sql);
     if (d->db.lastError().type() != QSqlError::NoError)
-        qWarning("Error executing sql command: %s",
-                 d->db.lastError().text().toLatin1().data());
+        qWarning("Error executing sql command: %s; Command=%s",
+                 d->db.lastError().text().toLatin1().data(),
+                 sql.toUtf8().constData());
     return q;
 }
 
@@ -504,10 +511,12 @@ void Database::add(TableSetBase *t)
     tableSets.insert(t);
 }
 
-void Database::saveChanges()
+int Database::saveChanges()
 {
+    int rowsAffected = 0;
     foreach (TableSetBase *ts, tableSets)
-        ts->save(this);
+        rowsAffected += ts->save(this);
+    return rowsAffected;
 }
 
 void Database::cleanUp()
diff --git a/src/database.h b/src/database.h
index 79dd6e9..96aa277 100644
--- a/src/database.h
+++ b/src/database.h
@@ -54,7 +54,7 @@ public:
     QSqlQuery exec(QString sql);
 
     void add(TableSetBase *);
-    void saveChanges();
+    int saveChanges();
     void cleanUp();
 
     QString databaseName() const;
diff --git a/src/database_p.h b/src/database_p.h
index 5a19e95..ac01411 100644
--- a/src/database_p.h
+++ b/src/database_p.h
@@ -44,7 +44,7 @@ public:
     void createChangeLogs();
     bool storeScheemaInDB();
     DatabaseModel getLastScheema();
-    void getCurrectScheema();
+    bool getCurrectScheema();
 
     QSqlDatabase db;
 
@@ -56,13 +56,15 @@ public:
     QString connectionName;
     QString driver;
 
-    QHash<QString, QString> tables;
 
     SqlGeneratorBase *sqlGenertor;
     DatabaseModel currentModel;
 
     TableSet<ChangeLogTable> *changeLogs;
 
+    QT_DEPRECATED
+    QHash<QString, QString> tables;
+    static QMap<QString, DatabaseModel> allTableMaps;
     static int lastId;
 };
 
diff --git a/src/databasemodel.cpp b/src/databasemodel.cpp
index 44e74e1..c8dc6d2 100644
--- a/src/databasemodel.cpp
+++ b/src/databasemodel.cpp
@@ -43,6 +43,10 @@ TableModel *DatabaseModel::model(QString tableName) const
         if(s->name() == tableName)
             return s;
     }
+
+    qWarning("Table with name '%s' not found in model",
+             qUtf8Printable(tableName));
+    Q_UNREACHABLE();
     return 0;
 }
 
@@ -53,6 +57,10 @@ TableModel *DatabaseModel::modelByClass(QString className) const
         if(s->className() == className)
             return s;
     }
+
+    qWarning("Table with class name '%s' not found in model",
+             qUtf8Printable(className));
+    Q_UNREACHABLE();
     return 0;
 }
 
diff --git a/src/query.h b/src/query.h
index ff128a8..1c3b02b 100644
--- a/src/query.h
+++ b/src/query.h
@@ -56,10 +56,7 @@ public:
 
     QVariant max(FieldPhrase<int> &f);
     QVariant min(FieldPhrase<int> &f);
-    QVariant average(FieldPhrase<int> &f){
-        //TODO: ...
-        return QVariant();
-    }
+    QVariant average(FieldPhrase<int> &f);
 
     Query<T> *join(const QString &tableName);
     Query<T> *setWhere(WherePhrase where);
@@ -87,8 +84,8 @@ Q_OUTOFLINE_TEMPLATE Query<T>::Query(Database *database, TableSetBase *tableSet)
 
     d->database = database;
     d->tableSet = tableSet;
-    d->tableName = TableModel::findByClassName(T::staticMetaObject.className())->name();
-                //d->database->tableName(T::staticMetaObject.className());
+    d->tableName = //TableModel::findByClassName(T::staticMetaObject.className())->name();
+                d->database->model().modelByClass(T::staticMetaObject.className())->name();
 }
 
 template<class T>
@@ -113,17 +110,18 @@ Q_OUTOFLINE_TEMPLATE QList<T *> Query<T>::toList(int count)
                     d->orderPhrases,
                     d->tableName,
                     d->joinClassName);
-    qDebug() << "sql="<<sql;
     QSqlQuery q = d->database->exec(sql);
 
-    QString pk = TableModel::findByName(d->tableName)->primaryKey();
-//    QString pk = d->database->model().model(d->tableName)->primaryKey();
+//    QString pk = TableModel::findByName(d->tableName)->primaryKey();
+    QString pk = d->database->model().model(d->tableName)->primaryKey();
     QVariant lastPkValue = QVariant();
     int childTypeId = 0;
     T *lastRow = 0;
     TableSetBase *childTableSet;
-    QStringList masterFields = TableModel::findByName(d->tableName)->fieldsNames();
-    //QStringList masterFields = d->database->model().model(d->tableName)->fieldsNames();
+
+    //FIXME: getting table error
+//    QStringList masterFields = TableModel::findByName(d->tableName)->fieldsNames();
+    QStringList masterFields = d->database->model().model(d->tableName)->fieldsNames();
     QStringList childFields;
     if(!d->joinClassName.isNull()) {
         TableModel *joinTableModel = TableModel::findByClassName(d->joinClassName);
@@ -131,8 +129,8 @@ Q_OUTOFLINE_TEMPLATE QList<T *> Query<T>::toList(int count)
 //            childFields = d->database->model().modelByClass(d->joinClassName)->fieldsNames();
             childFields = TableModel::findByClassName(d->joinClassName)->fieldsNames();
             QString joinTableName = d->database->tableName(d->joinClassName);
-//            childTypeId = d->database->model().model(joinTableName)->typeId();
-            childTypeId = TableModel::findByName(joinTableName)->typeId();
+            childTypeId = d->database->model().model(joinTableName)->typeId();
+//            childTypeId = TableModel::findByName(joinTableName)->typeId();
         }
     }
 
@@ -200,6 +198,7 @@ Q_OUTOFLINE_TEMPLATE int Query<T>::count()
     d->select = "COUNT(*)";
     QSqlQuery q = d->database->exec(d->database->sqlGenertor()->selectCommand("COUNT(*)", d->wheres, d->orders, d->tableName, d->joinClassName));
 
+    qDebug() << "sql="<<d->database->sqlGenertor()->selectCommand("COUNT(*)", d->wheres, d->orders, d->tableName, d->joinClassName);
     if(q.next())
         return q.value(0).toInt();
     return 0;
@@ -227,6 +226,18 @@ Q_OUTOFLINE_TEMPLATE QVariant Query<T>::min(FieldPhrase<int> &f){
     return 0;
 }
 
+template<class T>
+Q_OUTOFLINE_TEMPLATE QVariant Query<T>::average(FieldPhrase<int> &f)
+{
+    Q_D(Query);
+
+    QSqlQuery q = d->database->exec(d->database->sqlGenertor()->selectCommand("AVG(" + f.data()->text + ")", d->wheres, d->orders, d->tableName, d->joinClassName));
+
+    if(q.next())
+        return q.value(0).toInt();
+    return 0;
+}
+
 template<class T>
 Q_OUTOFLINE_TEMPLATE int Query<T>::remove()
 {
diff --git a/src/sqlgeneratorbase.cpp b/src/sqlgeneratorbase.cpp
index 2afea5a..3c69fe5 100644
--- a/src/sqlgeneratorbase.cpp
+++ b/src/sqlgeneratorbase.cpp
@@ -51,6 +51,7 @@ QString SqlGeneratorBase::masterDatabaseName(QString databaseName)
 
 QString SqlGeneratorBase::saveRecord(Table *t, QString tableName)
 {
+    Q_ASSERT(!tableName.isEmpty() && !tableName.isNull());
     switch(t->status()){
     case Table::Added:
         return insertRecord(t, tableName);
diff --git a/src/table.cpp b/src/table.cpp
index 2825e62..e8b62d6 100644
--- a/src/table.cpp
+++ b/src/table.cpp
@@ -121,7 +121,7 @@ void Table::setTableSet(TableSetBase *parent)
     _tableSet->add(this);
 }
 
-void Table::save(Database *db)
+int Table::save(Database *db)
 {
     QSqlQuery q = db->exec(db->sqlGenertor()->saveRecord(this, db->tableName(metaObject()->className())));
 
@@ -131,6 +131,8 @@ void Table::save(Database *db)
     foreach(TableSetBase *ts, tableSets)
         ts->save(db);
     setStatus(FeatchedFromDB);
+
+    return q.numRowsAffected();
 }
 
 Table::Status Table::status() const
diff --git a/src/table.h b/src/table.h
index 3df4ee5..ca5d411 100644
--- a/src/table.h
+++ b/src/table.h
@@ -49,7 +49,7 @@ public:
     };
 
     void add(TableSetBase *);
-    void save(Database *db);
+    int save(Database *db);
 
     QString primaryKey() const;
     bool isPrimaryKeyAutoIncrement() const;
diff --git a/src/tablemodel.cpp b/src/tablemodel.cpp
index cc3f9cf..32688bc 100644
--- a/src/tablemodel.cpp
+++ b/src/tablemodel.cpp
@@ -103,13 +103,13 @@ TableModel *TableModel::findByTypeId(int typeId)
     return 0;
 }
 
-TableModel *TableModel::findByName(QString name)
-{
-    foreach (TableModel *model, _allModels)
-        if(model->name() == name)
-            return model;
-    return 0;
-}
+//TableModel *TableModel::findByName(QString name)
+//{
+//    foreach (TableModel *model, _allModels)
+//        if(model->name() == name)
+//            return model;
+//    return 0;
+//}
 
 TableModel *TableModel::findByClassName(QString className)
 {
@@ -146,6 +146,10 @@ bool TableModel::operator !=(const TableModel &t) const
 
 TableModel::TableModel(int typeId, QString tableName)
 {
+    //TODO: check that
+//    if  (findByTypeId(typeId))
+//        return;
+
     const QMetaObject *tableMetaObject = QMetaType::metaObjectForType(typeId);
 
     _typeId = typeId;
@@ -238,8 +242,8 @@ TableModel::TableModel(int typeId, QString tableName)
         }
     }
 
-    _allModels.insert(this);
-    qDebug() << "all models"<<_allModels;
+    if(!findByTypeId(typeId) && !tableName.isNull())
+        _allModels.insert(this);
 }
 
 /*
@@ -267,7 +271,6 @@ TableModel::TableModel(QJsonObject json, QString tableName)
         QJsonObject fieldObject = fields.value(key).toObject();
         FieldModel *f = new FieldModel;
         f->name = fieldObject.value(__NAME).toString();
-        qDebug() << "fieldObject.value(__TYPE).toString()"<<fieldObject.value(__TYPE).toString();
         f->type = QVariant::nameToType(fieldObject.value(__TYPE).toString().toLatin1().data());
 
         if(fieldObject.contains(__nut_NOT_NULL))
@@ -288,7 +291,6 @@ TableModel::TableModel(QJsonObject json, QString tableName)
         field(json.value(__nut_PRIMARY_KEY).toString())->isAutoIncrement = true;
 
     _allModels.insert(this);
-
 }
 
 QJsonObject TableModel::toJson() const
diff --git a/src/tablemodel.h b/src/tablemodel.h
index 36f040e..3e2b9c6 100644
--- a/src/tablemodel.h
+++ b/src/tablemodel.h
@@ -73,7 +73,7 @@ class TableModel
 {
 public:
 
-    TableModel(int typeId, QString tableName);
+    TableModel(int typeId, QString tableName = QString::null);
     TableModel(QJsonObject json, QString tableName);
 
     QJsonObject toJson() const;
@@ -103,7 +103,7 @@ public:
 
     static QSet<TableModel *> allModels();
     static TableModel *findByTypeId(int typeId);
-    static TableModel *findByName(QString name);
+//    static TableModel *findByName(QString name);
     static TableModel *findByClassName(QString className);
 
     bool operator ==(const TableModel &t) const;
diff --git a/src/tablesetbase.cpp b/src/tablesetbase.cpp
index b29a40b..e9bc7f5 100644
--- a/src/tablesetbase.cpp
+++ b/src/tablesetbase.cpp
@@ -35,8 +35,9 @@ TableSetBase::TableSetBase(Table *parent) : QObject(parent), _database(0), _tabl
     parent->add(this);
 }
 
-void TableSetBase::save(Database *db)
+int TableSetBase::save(Database *db)
 {
+    int rowsAffected = 0;
     foreach (Table *t, _tablesList) {
         if(_table)
             t->setParentTable(_table);
@@ -44,9 +45,11 @@ void TableSetBase::save(Database *db)
         if(t->status() == Table::Added
                 || t->status() == Table::Modified
                 || t->status() == Table::Deleted){
-            t->save(db);
+            rowsAffected += t->save(db);
         }
     }
+
+    return rowsAffected;
 }
 
 void TableSetBase::clearChilds()
diff --git a/src/tablesetbase_p.h b/src/tablesetbase_p.h
index 307e0e0..50dd5a6 100644
--- a/src/tablesetbase_p.h
+++ b/src/tablesetbase_p.h
@@ -38,7 +38,7 @@ public:
     TableSetBase(Database *parent);
     TableSetBase(Table *parent);
 
-    virtual void save(Database *db);
+    virtual int save(Database *db);
     void clearChilds();
     void add(Table* t);
     QString childClassName() const;