diff --git a/3rdparty/serializer b/3rdparty/serializer
index e2d8a72..b3c550c 160000
--- a/3rdparty/serializer
+++ b/3rdparty/serializer
@@ -1 +1 @@
-Subproject commit e2d8a726ef1396c47bf35347ea8b55ca47c6af3b
+Subproject commit b3c550c5bb7c570b1b10492fcedf287c1915af39
diff --git a/ci-test-init.pri b/ci-test-init.pri
index 021efb9..c3d1f7b 100644
--- a/ci-test-init.pri
+++ b/ci-test-init.pri
@@ -1 +1 @@
-QT -= gui
+#QT -= gui
diff --git a/src/database.cpp b/src/database.cpp
index e6ebfd3..2b38e67 100644
--- a/src/database.cpp
+++ b/src/database.cpp
@@ -625,6 +625,12 @@ void Database::add(TableSetBase *t)
 int Database::saveChanges(bool cleanUp)
 {
     Q_D(Database);
+
+    if (!d->db.isOpen()) {
+        qWarning("Database is not open");
+        return 0;
+    }
+
     int rowsAffected = 0;
     foreach (TableSetBase *ts, d->tableSets)
         rowsAffected += ts->save(this, cleanUp);
diff --git a/src/generators/sqlgeneratorbase.cpp b/src/generators/sqlgeneratorbase.cpp
index 22b0757..45460b3 100644
--- a/src/generators/sqlgeneratorbase.cpp
+++ b/src/generators/sqlgeneratorbase.cpp
@@ -152,6 +152,7 @@ QString SqlGeneratorBase::fieldDeclare(FieldModel *field)
 
 QStringList SqlGeneratorBase::constraints(TableModel *table)
 {
+    Q_UNUSED(table);
     return QStringList();
 }
 
diff --git a/src/table.cpp b/src/table.cpp
index c2c3636..b45f98d 100644
--- a/src/table.cpp
+++ b/src/table.cpp
@@ -45,7 +45,7 @@ Table::Table(QObject *parent) : QObject(parent),
 {
     Q_D(Table);
     d->status = NewCreated;
-    d->model = TableModel::findByClassName(metaObject()->className());
+//    d->model = TableModel::findByClassName(metaObject()->className());
 }
 
 Table::~Table()
@@ -86,15 +86,15 @@ QVariant Table::primaryValue() const
 void Table::propertyChanged(const QString &propName)
 {
     Q_D(Table);
-    if (!d->model)
-         d->model = TableModel::findByClassName(metaObject()->className());
+//    if (!d->model)
+//         d->model = TableModel::findByClassName(metaObject()->className());
 
-    if (!d->model)
-        qFatal ("model for class '%s' not found", qPrintable(metaObject()->className()));
+//    if (!d->model)
+//        qFatal ("model for class '%s' not found", qPrintable(metaObject()->className()));
 
-    foreach (FieldModel *f, d->model->fields())
-        if(f->isPrimaryKey && propName == f->name && f->isAutoIncrement)
-            return;
+//    foreach (FieldModel *f, d->model->fields())
+//        if(f->isPrimaryKey && propName == f->name && f->isAutoIncrement)
+//            return;
 
     d->changedProperties.insert(propName);
     if (d->status == FeatchedFromDB)
diff --git a/src/tablemodel.cpp b/src/tablemodel.cpp
index aa5d416..ce302be 100644
--- a/src/tablemodel.cpp
+++ b/src/tablemodel.cpp
@@ -300,6 +300,7 @@ TableModel::TableModel(const QJsonObject &json, const QString &tableName) : _typ
     QJsonObject relations = json.value(__FOREIGN_KEYS).toObject();
     foreach (QString key, fields.keys()) {
         QJsonObject fieldObject = fields.value(key).toObject();
+        //TODO: use FieldModel(QJsonObject) ctor
         auto *f = new FieldModel;
         f->name = fieldObject.value(__NAME).toString();
         f->type = static_cast<QMetaType::Type>(QMetaType::type(fieldObject.value(__TYPE).toString().toLatin1().data()));
diff --git a/test/common/consts.h b/test/common/consts.h
index 1a1a479..901bd2a 100644
--- a/test/common/consts.h
+++ b/test/common/consts.h
@@ -1,6 +1,8 @@
 #ifndef CONSTS_H
 #define CONSTS_H
 
+#include <qsystemdetection.h>
+
 #define REGISTER(x) qDebug() << (#x) << "type id:" << qMetaTypeId<x*>()
 #define PRINT(x) qDebug() << (#x "=") << (x);
 #define TIC()  QElapsedTimer timer; timer.start()
@@ -11,8 +13,8 @@
 #define DRIVER "QPSQL"
 #define DATABASE QString("nut_test_%1_db").arg(metaObject()->className()).toLower()
 #define HOST "127.0.0.1"
-#define USERNAME "postgres"
-#define PASSWORD ""
+#define USERNAME "nut"
+#define PASSWORD "856856"
 
 #ifdef Q_OS_LINUX
 #   define OS "Linux"
diff --git a/test/common/nut-lib.pri b/test/common/nut-lib.pri
index 02daed5..8bf4a5b 100644
--- a/test/common/nut-lib.pri
+++ b/test/common/nut-lib.pri
@@ -1,10 +1,10 @@
-win32 {
-	CONFIG(debug,debug|release):   LIBDIR = $$absolute_path($$OUT_PWD/../../src/debug)
-	CONFIG(release,debug|release): LIBDIR = $$absolute_path($$OUT_PWD/../../src/release)
-} else {
-	LIBDIR = $$absolute_path($$OUT_PWD/../../src)
-}
-
-LIBS += -L$$LIBDIR -lnut
+#win32 {
+#	CONFIG(debug,debug|release):   LIBDIR = $$absolute_path($$OUT_PWD/../../src/debug)
+#	CONFIG(release,debug|release): LIBDIR = $$absolute_path($$OUT_PWD/../../src/release)
+#} else {
+#	LIBDIR = $$absolute_path($$OUT_PWD/../../src)
+#}
 
+#LIBS += -L$$LIBDIR -lnut
+include(../../src/src.pri)
 INCLUDEPATH += $$PWD/../../src $$PWD/../common
diff --git a/test/tst_json/tst_json.cpp b/test/tst_json/tst_json.cpp
index 3129b16..3ae5b61 100644
--- a/test/tst_json/tst_json.cpp
+++ b/test/tst_json/tst_json.cpp
@@ -38,7 +38,15 @@ void TestJson::store()
     DB db;
     initDb(db);
 
-    QTEST_ASSERT(db.open());
+    db.open();
+
+    Table *t = new Table;
+    QJsonDocument doc = QJsonDocument::fromJson("{a: 4, b:3.14}");
+    t->setDoc(doc);
+    db.sampleTable()->append(t);
+    db.saveChanges(true);
+
+//    QTEST_ASSERT(db.open());
 }
 
 QTEST_APPLESS_MAIN(TestJson)