diff --git a/database.cpp b/database.cpp
index 0b10e11..2c2791a 100644
--- a/database.cpp
+++ b/database.cpp
@@ -18,7 +18,7 @@
 #include "exceptions.h"
 #include "table.h"
 
-Core::DataBase::DataBase(const QString& p_name, uint16_t mapSize):
+DataBase::DataBase(const QString& p_name, uint16_t mapSize):
     name(p_name.toStdString()),
     opened(false),
     size(mapSize),
@@ -27,7 +27,7 @@ Core::DataBase::DataBase(const QString& p_name, uint16_t mapSize):
 {
 }
 
-Core::DataBase::~DataBase()
+DataBase::~DataBase()
 {
     close();
     for (const std::pair<const std::string, _Table*>& pair : tables) {
@@ -35,7 +35,7 @@ Core::DataBase::~DataBase()
     }
 }
 
-void Core::DataBase::close()
+void DataBase::close()
 {
     if (opened) {
         for (const std::pair<const std::string, _Table*>& pair : tables) {
@@ -47,7 +47,7 @@ void Core::DataBase::close()
     }
 }
 
-void Core::DataBase::open()
+void DataBase::open()
 {
     if (!opened) {
         mdb_env_create(&environment);
@@ -71,7 +71,7 @@ void Core::DataBase::open()
 
         for (const std::pair<const std::string, _Table*>& pair : tables) {
             _Table* table = pair.second;
-            int rc = mdb_dbi_open(txn, pair.first.c_str(), MDB_CREATE, &table->dbi);
+            int rc = table->createTable(txn);
             if (rc) {
                 throw Unknown(name, mdb_strerror(rc));
             }
@@ -82,18 +82,9 @@ void Core::DataBase::open()
     }
 }
 
-QString Core::DataBase::getName() const
+QString DataBase::getName() const
 {
     return QString::fromStdString(name);
 }
 
-template <class K, class V>
-Core::DataBase::Table<K, V>* Core::DataBase::addTable(const QString& p_name) {
-    std::string nm = p_name.toStdString();
-    if (opened) {
-        throw Core::DataBase::Opened(name, nm);
-    }
-    Core::DataBase::Table<K, V>* table = new Core::DataBase::Table<K, V>(nm, this);
-    tables.insert(std::make_pair(nm, table));
-    return table;
-}
+
diff --git a/database.h b/database.h
index 685e3fe..815ae61 100644
--- a/database.h
+++ b/database.h
@@ -25,8 +25,6 @@
 #include <QDir>
 #include <lmdb.h>
 
-namespace Core {
-
 class DataBase
 {
     class _Table;
@@ -63,6 +61,17 @@ private:
     std::map<std::string, _Table*> tables;
 };
 
+#include "exceptions.h"
+
+template <class K, class V>
+DataBase::Table<K, V>* DataBase::addTable(const QString& p_name) {
+    std::string nm = p_name.toStdString();
+    if (opened) {
+        throw Opened(name, nm);
+    }
+    DataBase::Table<K, V>* table = new DataBase::Table<K, V>(nm, this);
+    tables.insert(std::make_pair(nm, (_Table*)table));
+    return table;
 }
 
 #endif // CORE_DATABASE_H
diff --git a/exceptions.cpp b/exceptions.cpp
index 0c0c7d5..ac607aa 100644
--- a/exceptions.cpp
+++ b/exceptions.cpp
@@ -16,14 +16,14 @@
 
 #include "exceptions.h"
 
-Core::DataBase::Directory::Directory(const std::string& p_path):
+DataBase::Directory::Directory(const std::string& p_path):
     Exception(),
     path(p_path) {}
 
-std::string Core::DataBase::Directory::getMessage() const {
+std::string DataBase::Directory::getMessage() const {
     return "Can't create directory for database at " + path;}
 
-Core::DataBase::Closed::Closed(
+DataBase::Closed::Closed(
     const std::string& p_operation,
     const std::string& p_dbName,
     const std::string& p_tableName
@@ -33,26 +33,26 @@ Core::DataBase::Closed::Closed(
     dbName(p_dbName),
     tableName(p_tableName) {}
 
-std::string Core::DataBase::Closed::getMessage() const {
+std::string DataBase::Closed::getMessage() const {
     return "An attempt to perform operation " + operation
             + " on closed database " + dbName
             + " on table " + tableName;
 }
 
-Core::DataBase::Opened::Opened(const std::string& p_dbName, const std::string& p_tableName):
+DataBase::Opened::Opened(const std::string& p_dbName, const std::string& p_tableName):
     Exception(),
     dbName(p_dbName),
     tableName(p_tableName) {}
 
 
-std::string Core::DataBase::Opened::getMessage() const {
+std::string DataBase::Opened::getMessage() const {
     return "An attempt to add table " + tableName
             + " to the database " + dbName
             + " but it's can't be done because the DataBase is already opened."
             + " Please add all tables before opening DataBase.";
 }
 
-Core::DataBase::NotFound::NotFound(
+DataBase::NotFound::NotFound(
     const std::string& p_key,
     const std::string& p_dbName,
     const std::string& p_tableName
@@ -62,12 +62,12 @@ Core::DataBase::NotFound::NotFound(
     dbName(p_dbName),
     tableName(p_tableName) {}
 
-std::string Core::DataBase::NotFound::getMessage() const {
+std::string DataBase::NotFound::getMessage() const {
     return "Element for id " + key + " wasn't found "
             + " in database " + dbName
             + " in table " + tableName;}
 
-Core::DataBase::Exist::Exist(
+DataBase::Exist::Exist(
     const std::string& p_key,
     const std::string& p_dbName,
     const std::string& p_tableName
@@ -77,14 +77,14 @@ Core::DataBase::Exist::Exist(
     dbName(p_dbName),
     tableName(p_tableName) {}
 
-std::string Core::DataBase::Exist::getMessage() const {
+std::string DataBase::Exist::getMessage() const {
     return "An attempt to insert element with key " + key
             + " to database " + dbName
             + " to table " + tableName
             + " but it already has an element with given id";
 }
 
-Core::DataBase::Unknown::Unknown(
+DataBase::Unknown::Unknown(
     const std::string& p_dbName,
     const std::string& message,
     const std::optional<std::string>& p_tableName
@@ -94,7 +94,7 @@ Core::DataBase::Unknown::Unknown(
     tableName(p_tableName),
     msg(message) {}
 
-std::string Core::DataBase::Unknown::getMessage() const
+std::string DataBase::Unknown::getMessage() const
 {
     std::string result = "Unknown error in database " + dbName;
     if (tableName.has_value()) {
diff --git a/exceptions.h b/exceptions.h
index 7e2bd34..e77f681 100644
--- a/exceptions.h
+++ b/exceptions.h
@@ -20,8 +20,6 @@
 #include "exception.h"
 #include "database.h"
 
-namespace Core {
-
 class DataBase::Directory: public Utils::Exception {
 public:
     Directory(const std::string& path);
@@ -84,5 +82,5 @@ private:
     std::optional<std::string> tableName;
     std::string msg;
 };
-}
+
 #endif //CORE_DATABASE_EXCEPTIONS_H
diff --git a/main.cpp b/main.cpp
index 505c051..3b2104a 100644
--- a/main.cpp
+++ b/main.cpp
@@ -4,38 +4,31 @@
 #include "table.h"
 
 
-template<class T>
-class Serializer {
-public:
-    Serializer(const T& value):val(value) {}
-
-    void print() {
-        std::cout << val << std::endl;
-    }
-
-    T val;
-};
-
-
-template<>
-class Serializer<int> {
-public:
-    Serializer(int v): value(v) {}
-
-    int value;
-};
-
 int main(int argc, char **argv) {
 
-    Core::DataBase base("test1");
-    Core::DataBase::Table<uint32_t, uint32_t>* table1 = base.addTable<uint32_t, uint32_t>("table1");
-    Core::DataBase::Table<QString, QString>* table2 = base.addTable<QString, QString>("table2");
+    DataBase base("test1");
+    DataBase::Table<uint32_t, uint32_t>* table1 = base.addTable<uint32_t, uint32_t>("table1");
+    DataBase::Table<QString, QString>* table2 = base.addTable<QString, QString>("table2");
 
     base.open();
 
-    table1->addRecord(1, 2);
+    try {
+        table1->addRecord(1, 2);
+    } catch (const DataBase::Exist& error) {
+        std::cout << error.getMessage() << std::endl;
+    }
 
+    uint32_t rec1 = table1->getRecord(1);
+    std::cout << "table1 record under 1 is " << rec1 << std::endl;
 
+    try {
+        table2->addRecord("hello", "world");
+    } catch (const DataBase::Exist& error) {
+        std::cout << error.getMessage() << std::endl;
+    }
+
+    QString rec2 = table2->getRecord("hello");
+    std::cout << "table2 record under hello is " << rec2.toStdString() << std::endl;
 
     return 0;
 }
diff --git a/serializer.h b/serializer.h
index db29197..992f3f4 100644
--- a/serializer.h
+++ b/serializer.h
@@ -23,8 +23,6 @@
 
 #include "database.h"
 
-namespace Core {
-
 template<class T>
 class DataBase::Serializer
 {
@@ -33,6 +31,7 @@ public:
     Serializer(const T& value);
     ~Serializer();
 
+    T deserialize(const MDB_val& value);
     MDB_val setData(const T& value);
     MDB_val getData();
     void clear();
@@ -47,6 +46,7 @@ private:
     QDataStream stream;
 };
 
-}
+#include "serializer.hpp"
+#include "serializer_uint32.hpp"
 
 #endif // CORE_DATABASE_SERIALIZER_H
diff --git a/serializer.hpp b/serializer.hpp
index 4a43c66..59305c0 100644
--- a/serializer.hpp
+++ b/serializer.hpp
@@ -14,57 +14,73 @@
 // You should have received a copy of the GNU General Public License
 // along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
+
+#ifndef CORE_DATABASE_SERIALIZER_HPP
+#define CORE_DATABASE_SERIALIZER_HPP
+
 #include "serializer.h"
 
 template<class T>
-Core::DataBase::Serializer<T>::Serializer() :
+DataBase::Serializer<T>::Serializer() :
     bytes(),
     buffer(&bytes),
     stream(&buffer)
 {
-    buffer.open(QIODevice::WriteOnly);
+    buffer.open(QIODevice::ReadWrite);
 }
 
 template<class T>
-Core::DataBase::Serializer<T>::Serializer(const T& value) :
+DataBase::Serializer<T>::Serializer(const T& value) :
     bytes(),
     buffer(&bytes),
     stream(&buffer)
 {
-    buffer.open(QIODevice::WriteOnly);
+    buffer.open(QIODevice::ReadWrite);
     _setValue(value);
 }
 
 template<class T>
-Core::DataBase::Serializer<T>::~Serializer() {
+DataBase::Serializer<T>::~Serializer() {
     buffer.close();
 }
 
 template<class T>
-MDB_val Core::DataBase::Serializer<T>::setData(const T& value) {
+MDB_val DataBase::Serializer<T>::setData(const T& value) {
     clear();
-    _setValue(value);
-    return getValue();
+    _setData(value);
+    return getData();
 }
 
 template<class T>
-void Core::DataBase::Serializer<T>::_setData(const T& value) {
+T DataBase::Serializer<T>::deserialize(const MDB_val& value) {
+    clear();
+    bytes.setRawData((char*)value.mv_data, value.mv_size);
+    T result;
+    stream >> result;
+
+    return result;
+}
+
+template<class T>
+void DataBase::Serializer<T>::_setData(const T& value) {
     stream << value;
 }
 
 template<class T>
-void Core::DataBase::Serializer<T>::clear() {
+void DataBase::Serializer<T>::clear() {
     if (buffer.pos() > 0) {
         buffer.seek(0);
     }
 }
 
 template<class T>
-MDB_val Core::DataBase::Serializer<T>::getData() {
+MDB_val DataBase::Serializer<T>::getData() {
     MDB_val val;
 
     val.mv_size = buffer.pos();
-    val.mv_data = (uint8_t*)bytes.data();
+    val.mv_data = (char*)bytes.data();
 
     return val;
 }
+
+#endif //CORE_DATABASE_SERIALIZER_HPP
diff --git a/serializer_uint32.hpp b/serializer_uint32.hpp
new file mode 100644
index 0000000..7c1832e
--- /dev/null
+++ b/serializer_uint32.hpp
@@ -0,0 +1,50 @@
+// Squawk messenger.
+// Copyright (C) 2019  Yury Gubich <blue@macaw.me>
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 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 General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+
+#ifndef CORE_DATABASE_SERIALIZER_UINT32_HPP
+#define CORE_DATABASE_SERIALIZER_UINT32_HPP
+
+template<>
+class DataBase::Serializer<uint32_t>
+{
+public:
+    Serializer():value(0) {};
+    Serializer(const uint32_t& p_value):value(p_value) {};
+    ~Serializer() {};
+
+    uint32_t deserialize(const MDB_val& data) {
+        std::memcpy(&value, data.mv_data, 4);
+        return value;
+    };
+    MDB_val setData(const uint32_t& data) {
+        value = data;
+        return getData();
+    };
+    MDB_val getData() {
+        MDB_val result;
+        result.mv_data = &value,
+        result.mv_size = 4;
+        return result;
+    };
+    void clear() {};    //not possible;
+
+private:
+    uint32_t value;
+};
+
+
+#endif //CORE_DATABASE_SERIALIZER_UINT32_HPP
diff --git a/table.cpp b/table.cpp
index 17b6e03..ea26110 100644
--- a/table.cpp
+++ b/table.cpp
@@ -16,11 +16,11 @@
 
 #include "table.h"
 
-Core::DataBase::_Table::_Table(const std::string& p_name, DataBase* parent):
+DataBase::_Table::_Table(const std::string& p_name, DataBase* parent):
     dbi(),
     db(parent),
     name(p_name)
 {
 }
 
-Core::DataBase::_Table::~_Table() {}
+DataBase::_Table::~_Table() {}
diff --git a/table.h b/table.h
index 1fadee5..0c25231 100644
--- a/table.h
+++ b/table.h
@@ -20,17 +20,23 @@
 #include "database.h"
 #include "serializer.h"
 
-namespace Core {
-
 class DataBase::_Table {
 public:
     _Table(const std::string& name, DataBase* parent);
     virtual ~_Table();
 
+    virtual int createTable(MDB_txn * transaction) = 0;
 public:
     MDB_dbi dbi;
     DataBase* db;
     const std::string name;
+
+protected:
+    template <class T>
+    int makeTable(MDB_txn* transaction);
+
+    template <class T>
+    static std::string toString(const T& value);
 };
 
 template <class K, class V>
@@ -47,16 +53,12 @@ public:
     V getRecord(const K& key) const;
 
 private:
-    Serializer<K> keySerializer;
-    Serializer<V> valueSerializer;
+    Serializer<K>* keySerializer;
+    Serializer<V>* valueSerializer;
+
+    int createTable(MDB_txn* transaction) override;
 };
 
-}
-
-namespace std {
-    std::string to_string(const QString& str);
-}
-
 #include "table.hpp"
 
 #endif // CORE_TABLE_H
diff --git a/table.hpp b/table.hpp
index ee6766c..9365ec5 100644
--- a/table.hpp
+++ b/table.hpp
@@ -20,26 +20,28 @@
 #include "table.h"
 #include "exceptions.h"
 
-template<typename K, typename V>
-Core::DataBase::Table<K, V>::Table(const std::string& p_name, Core::DataBase* parent):
+template<class K, class V>
+DataBase::Table<K, V>::Table(const std::string& p_name, DataBase* parent):
     _Table(p_name, parent),
-    keySerializer(),
-    valueSerializer()
+    keySerializer(new Serializer<K>()),
+    valueSerializer(new Serializer<V>())
 {
 }
 
-template<typename K, typename V>
-Core::DataBase::Table<K, V>::~Table() {
+template<class K, class V>
+DataBase::Table<K, V>::~Table() {
+    delete valueSerializer;
+    delete keySerializer;
 }
 
-template<typename K, typename V>
-void Core::DataBase::Table<K, V>::addRecord(const K& key, const V& value) {
+template<class K, class V>
+void DataBase::Table<K, V>::addRecord(const K& key, const V& value) {
     if (!db->opened) {
         throw Closed("addRecord", db->name, name);
     }
 
-    MDB_val lmdbKey = keySerializer.setData(key);
-    MDB_val lmdbData = valueSerializer.setData(value);
+    MDB_val lmdbKey = keySerializer->setData(key);
+    MDB_val lmdbData = valueSerializer->setData(value);
     MDB_txn *txn;
     mdb_txn_begin(db->environment, NULL, 0, &txn);
     int rc;
@@ -47,7 +49,7 @@ void Core::DataBase::Table<K, V>::addRecord(const K& key, const V& value) {
     if (rc != 0) {
         mdb_txn_abort(txn);
         if (rc == MDB_KEYEXIST) {
-            throw Exist(std::to_string(key), db->name, name);
+            throw Exist(toString(key), db->name, name);
         } else {
             throw Unknown(db->name, mdb_strerror(rc), name);
         }
@@ -58,14 +60,14 @@ void Core::DataBase::Table<K, V>::addRecord(const K& key, const V& value) {
 
 
 
-template<typename K, typename V>
-void Core::DataBase::Table<K, V>::changeRecord(const K& key, const V& value) {
+template<class K, class V>
+void DataBase::Table<K, V>::changeRecord(const K& key, const V& value) {
     if (!db->opened) {
         throw Closed("changeRecord", db->name, name);
     }
 
-    MDB_val lmdbKey = keySerializer.setData(key);
-    MDB_val lmdbData = valueSerializer.setData(value);
+    MDB_val lmdbKey = keySerializer->setData(key);
+    MDB_val lmdbData = valueSerializer->setData(value);
     MDB_txn *txn;
     mdb_txn_begin(db->environment, NULL, 0, &txn);
     int rc;
@@ -80,13 +82,13 @@ void Core::DataBase::Table<K, V>::changeRecord(const K& key, const V& value) {
     }
 }
 
-template<typename K, typename V>
-V Core::DataBase::Table<K, V>::getRecord(const K& key) const {
+template<class K, class V>
+V DataBase::Table<K, V>::getRecord(const K& key) const {
     if (!db->opened) {
         throw Closed("getRecord", db->name, name);
     }
 
-    MDB_val lmdbKey = keySerializer.setData(key);
+    MDB_val lmdbKey = keySerializer->setData(key);
     MDB_val lmdbData;
 
     MDB_txn *txn;
@@ -96,26 +98,25 @@ V Core::DataBase::Table<K, V>::getRecord(const K& key) const {
     if (rc) {
         mdb_txn_abort(txn);
         if (rc == MDB_NOTFOUND) {
-            throw NotFound(std::to_string(key), db->name, name);
+            throw NotFound(toString(key), db->name, name);
         } else {
             throw Unknown(db->name, mdb_strerror(rc), name);
         }
     } else {
-        V value;
-        lmdbData >> value;
+        V value = valueSerializer->deserialize(lmdbData);
         mdb_txn_abort(txn);
 
         return value;
     }
 }
 
-template<typename K, typename V>
-void Core::DataBase::Table<K, V>::removeRecord(const K& key) {
+template<class K, class V>
+void DataBase::Table<K, V>::removeRecord(const K& key) {
     if (!db->opened) {
         throw Closed("removeRecord", db->name, name);
     }
 
-    MDB_val lmdbKey = keySerializer.setData(key);
+    MDB_val lmdbKey = keySerializer->setData(key);
 
     MDB_txn *txn;
     int rc;
@@ -124,7 +125,7 @@ void Core::DataBase::Table<K, V>::removeRecord(const K& key) {
     if (rc) {
         mdb_txn_abort(txn);
         if (rc == MDB_NOTFOUND) {
-            throw NotFound(std::to_string(key), db->name, name);
+            throw NotFound(toString(key), db->name, name);
         } else {
             throw Unknown(db->name, mdb_strerror(rc), name);
         }
@@ -133,8 +134,29 @@ void Core::DataBase::Table<K, V>::removeRecord(const K& key) {
     }
 }
 
-std::string std::to_string(const QString& str) {
-    return str.toStdString();
+template<class K, class V>
+int DataBase::Table<K, V>::createTable(MDB_txn* transaction) {
+    return makeTable<K>(transaction);
+}
+
+template<class K>
+inline int DataBase::_Table::makeTable(MDB_txn* transaction) {
+    return mdb_dbi_open(transaction, name.c_str(), MDB_CREATE, &dbi);
+}
+
+template<>
+inline int DataBase::_Table::makeTable<uint32_t>(MDB_txn* transaction) {
+    return mdb_dbi_open(transaction, name.c_str(), MDB_CREATE | MDB_INTEGERKEY, &dbi);
+}
+
+template<class T>
+inline std::string DataBase::_Table::toString(const T& value) {
+    return std::to_string(value);
+}
+
+template<>
+inline std::string DataBase::_Table::toString(const QString& value) {
+    return value.toStdString();
 }
 
 #endif //CORE_TABLE_HPP