diff --git a/src/KDb.cpp b/src/KDb.cpp
index b25c7222..eca23c46 100644
--- a/src/KDb.cpp
+++ b/src/KDb.cpp
@@ -1,2238 +1,2238 @@
 /* This file is part of the KDE project
    Copyright (C) 2004-2017 Jarosław Staniek <staniek@kde.org>
    Copyright (c) 2006, 2007 Thomas Braxton <kde.braxton@gmail.com>
    Copyright (c) 1999 Preston Brown <pbrown@kde.org>
    Copyright (c) 1997 Matthias Kalle Dalheimer <kalle@kde.org>
 
    This library 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 library 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 library; see the file COPYING.LIB.  If not, write to
    the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  * Boston, MA 02110-1301, USA.
 */
 
 #include "KDb.h"
 #include "KDbConnectionData.h"
 #include "KDbConnection.h"
 #include "KDbCursor.h"
 #include "kdb_debug.h"
 #include "KDbDriverBehavior.h"
 #include "KDbDriverManager.h"
 #include "KDbDriver_p.h"
 #include "KDbLookupFieldSchema.h"
 #include "KDbMessageHandler.h"
 #include "KDbNativeStatementBuilder.h"
 #include "KDb_p.h"
 #include "KDbQuerySchema.h"
 #include "KDbRecordData.h"
 #include "KDbSqlResult.h"
 #include "KDbTableOrQuerySchema.h"
 #include "KDbVersionInfo.h"
 #include "transliteration/transliteration_table.h"
 
 #include <QMap>
 #include <QHash>
 #include <QBuffer>
 #include <QPixmap>
 #include <QSet>
 #include <QTimer>
 #include <QThread>
 #include <QProgressDialog>
 #include <QDomNode>
 #include <QApplication>
 #include <QDir>
 #include <QProcess>
 #include <QtDebug>
 
 #include <limits>
 #include <memory>
 
 Q_DECLARE_METATYPE(KDbField::Type)
 
 class ConnectionTestDialog;
 
 class ConnectionTestThread : public QThread
 {
     Q_OBJECT
 public:
     ConnectionTestThread(ConnectionTestDialog *dlg, const KDbConnectionData& connData);
     void run() override;
 Q_SIGNALS:
     void error(const QString& msg, const QString& details);
 protected:
     void emitError(const KDbResultable& KDbResultable);
 
     ConnectionTestDialog* m_dlg;
     KDbConnectionData m_connData;
     KDbDriver *m_driver;
 private:
     Q_DISABLE_COPY(ConnectionTestThread)
 };
 
 class ConnectionTestDialog : public QProgressDialog // krazy:exclude=qclasses
 {
     Q_OBJECT
 public:
     ConnectionTestDialog(const KDbConnectionData& data, KDbMessageHandler* msgHandler,
                          QWidget* parent = nullptr);
     ~ConnectionTestDialog() override;
 
     int exec() override;
 
 public Q_SLOTS:
     void error(const QString& msg, const QString& details);
 
 protected Q_SLOTS:
     void slotTimeout();
     void accept() override;
     void reject() override;
 
 protected:
     void finish();
 
     QPointer<ConnectionTestThread> m_thread;
     KDbConnectionData m_connData;
     QTimer m_timer;
     KDbMessageHandler* m_msgHandler;
     int m_elapsedTime;
     bool m_error;
     QString m_msg;
     QString m_details;
     bool m_stopWaiting;
 
 private:
     Q_DISABLE_COPY(ConnectionTestDialog)
 };
 
 ConnectionTestThread::ConnectionTestThread(ConnectionTestDialog* dlg, const KDbConnectionData& connData)
         : m_dlg(dlg), m_connData(connData)
 {
     connect(this, SIGNAL(error(QString,QString)),
             dlg, SLOT(error(QString,QString)), Qt::QueuedConnection);
 
     // try to load driver now because it's not supported in different thread
     KDbDriverManager manager;
     m_driver = manager.driver(m_connData.driverId());
     if (manager.result().isError()) {
         emitError(*manager.resultable());
         m_driver = nullptr;
     }
 }
 
 void ConnectionTestThread::emitError(const KDbResultable& KDbResultable)
 {
     QString msg;
     QString details;
     KDb::getHTMLErrorMesage(KDbResultable, &msg, &details);
     emit error(msg, details);
 }
 
 void ConnectionTestThread::run()
 {
     if (!m_driver) {
         return;
     }
     QScopedPointer<KDbConnection> conn(m_driver->createConnection(m_connData));
     if (conn.isNull() || m_driver->result().isError()) {
         emitError(*m_driver);
         return;
     }
     if (!conn->connect() || conn->result().isError()) {
         emitError(*conn);
         return;
     }
     // SQL database backends like PostgreSQL require executing "USE database"
     // if we really want to know connection to the server succeeded.
     QString tmpDbName;
     if (!conn->useTemporaryDatabaseIfNeeded(&tmpDbName)) {
         emitError(*conn);
         return;
     }
     if (!tmpDbName.isEmpty()) {
         if (!conn->closeDatabase()) {
             emitError(*conn);
         }
     }
     emitError(KDbResultable());
 }
 
 ConnectionTestDialog::ConnectionTestDialog(const KDbConnectionData& data,
         KDbMessageHandler* msgHandler, QWidget* parent)
         : QProgressDialog(parent)
         , m_thread(new ConnectionTestThread(this, data))
         , m_connData(data)
         , m_msgHandler(msgHandler)
         , m_elapsedTime(0)
         , m_error(false)
         , m_stopWaiting(false)
 {
     setWindowTitle(tr("Test Connection", "Dialog's title: testing database connection"));
     setLabelText(tr("Testing connection to \"%1\" database server...")
                  .arg(data.toUserVisibleString()));
     setModal(true);
     setRange(0, 0); //to show busy indicator
     connect(&m_timer, SIGNAL(timeout()), this, SLOT(slotTimeout()));
     adjustSize();
     resize(250, height());
 }
 
 ConnectionTestDialog::~ConnectionTestDialog()
 {
     if (m_thread->isRunning()) {
         m_thread->terminate();
     }
     m_thread->deleteLater();
 }
 
 int ConnectionTestDialog::exec()
 {
     //kdbDebug() << "tid:" << QThread::currentThread() << "this_thread:" << thread();
     m_timer.start(20);
     m_thread->start();
     const int res = QProgressDialog::exec(); // krazy:exclude=qclasses
     m_thread->wait();
     m_timer.stop();
     return res;
 }
 
 void ConnectionTestDialog::slotTimeout()
 {
     //kdbDebug() << "tid:" << QThread::currentThread() << "this_thread:" << thread();
     //kdbDebug() << m_error;
     bool notResponding = false;
     if (m_elapsedTime >= 1000*5) {//5 seconds
         m_stopWaiting = true;
         notResponding = true;
     }
     //kdbDebug() << m_elapsedTime << m_stopWaiting << notResponding;
     if (m_stopWaiting) {
         m_timer.disconnect(this);
         m_timer.stop();
         QString message;
         QString details;
         KDbMessageHandler::MessageType type;
         if (m_error) {
             reject();
             //kdbDebug() << "after reject";
             message = tr("Test connection to \"%1\" database server failed.")
                          .arg(m_connData.toUserVisibleString());
             details = m_msg;
             if (!m_details.isEmpty()) {
                 details += QLatin1Char('\n') + m_details;
             }
             type = KDbMessageHandler::Sorry;
             m_error = false;
         } else if (notResponding) {
             reject();
             //kdbDebug() << "after reject";
             message = tr("Test connection to \"%1\" database server failed. The server is not responding.")
                          .arg(m_connData.toUserVisibleString());
             type = KDbMessageHandler::Sorry;
         } else {
             accept();
             //kdbDebug() << "after accept";
             message = tr("Test connection to \"%1\" database server established successfully.")
                          .arg(m_connData.toUserVisibleString()),
             type = KDbMessageHandler::Information;
         }
         if (m_msgHandler) {
             m_msgHandler->showErrorMessage(type, message, details, tr("Test Connection"));
         }
         return;
     }
     m_elapsedTime += 20;
     setValue(m_elapsedTime);
 }
 
 void ConnectionTestDialog::error(const QString& msg, const QString& details)
 {
     //kdbDebug() << "tid:" << QThread::currentThread() << "this_thread:" << thread();
     //kdbDebug() << msg << details;
     m_stopWaiting = true;
     m_msg = msg;
     m_details = details;
     m_error = !msg.isEmpty() || !details.isEmpty();
     if (m_error) {
         kdbDebug() << "Error:" << msg << details;
     }
 }
 
 void ConnectionTestDialog::accept()
 {
     finish();
     QProgressDialog::accept(); // krazy:exclude=qclasses
 }
 
 void ConnectionTestDialog::reject()
 {
     finish();
     QProgressDialog::reject(); // krazy:exclude=qclasses
 }
 
 void ConnectionTestDialog::finish()
 {
     if (m_thread->isRunning()) {
         m_thread->terminate();
     }
     m_timer.disconnect(this);
     m_timer.stop();
 }
 
 // ----
 
 //! @return hex digit converted to integer (0 to 15), 0xFF on failure
 inline static unsigned char hexDigitToInt(char digit)
 {
     if (digit >= '0' && digit <= '9') {
         return digit - '0';
     }
     if (digit >= 'a' && digit <= 'f') {
         return digit - 'a' + 10;
     }
     if (digit >= 'A' && digit <= 'F') {
         return digit - 'A' + 10;
     }
     return 0xFF;
 }
 
 //! Converts textual representation @a data of a hex number (@a length digits) to a byte array @a array
 //! @return true on success and false if @a data contains characters that are not hex digits.
 //! true is returned for empty @a data as well.
 inline static bool hexToByteArrayInternal(const char* data, int length, QByteArray *array)
 {
     Q_ASSERT(length >= 0);
     Q_ASSERT(data || length == 0);
     array->resize(length / 2 + length % 2);
     for(int i = 0; length > 0; --length, ++data, ++i) {
         unsigned char d1 = hexDigitToInt(data[0]);
         unsigned char d2;
         if (i == 0 && (length % 2) == 1) { // odd number of digits; no leading 0
             d2 = d1;
             d1 = 0;
         }
         else {
             --length;
             ++data;
             d2 = hexDigitToInt(data[0]);
         }
         if (d1 == 0xFF || d2 == 0xFF) {
             return false;
         }
         (*array)[i] = (d1 << 4) + d2;
     }
     return true;
 }
 
 KDbVersionInfo KDb::version()
 {
     return KDbVersionInfo(
         KDB_VERSION_MAJOR, KDB_VERSION_MINOR, KDB_VERSION_PATCH);
 }
 
 bool KDb::deleteRecords(KDbConnection* conn, const QString &tableName,
                         const QString &keyname, KDbField::Type keytype, const QVariant &keyval)
 {
     return conn
         ? conn->executeSql(KDbEscapedString("DELETE FROM %1 WHERE %2=%3")
                                .arg(conn->escapeIdentifier(tableName))
                                .arg(conn->escapeIdentifier(keyname))
                                .arg(conn->driver()->valueToSql(keytype, keyval)))
         : false;
 }
 
 bool KDb::deleteRecords(KDbConnection* conn, const QString &tableName,
                         const QString &keyname1, KDbField::Type keytype1, const QVariant& keyval1,
                         const QString &keyname2, KDbField::Type keytype2, const QVariant& keyval2)
 {
     return conn
         ? conn->executeSql(KDbEscapedString("DELETE FROM %1 WHERE %2=%3 AND %4=%5")
                                .arg(conn->escapeIdentifier(tableName))
                                .arg(conn->escapeIdentifier(keyname1))
                                .arg(conn->driver()->valueToSql(keytype1, keyval1))
                                .arg(conn->escapeIdentifier(keyname2))
                                .arg(conn->driver()->valueToSql(keytype2, keyval2)))
         : false;
 }
 
 bool KDb::deleteRecords(KDbConnection* conn, const QString &tableName,
                         const QString &keyname1, KDbField::Type keytype1, const QVariant& keyval1,
                         const QString &keyname2, KDbField::Type keytype2, const QVariant& keyval2,
                         const QString &keyname3, KDbField::Type keytype3, const QVariant& keyval3)
 {
     return conn
         ? conn->executeSql(KDbEscapedString("DELETE FROM %1 WHERE %2=%3 AND %4=%5 AND %6=%7")
                                .arg(conn->escapeIdentifier(tableName))
                                .arg(conn->escapeIdentifier(keyname1))
                                .arg(conn->driver()->valueToSql(keytype1, keyval1))
                                .arg(conn->escapeIdentifier(keyname2))
                                .arg(conn->driver()->valueToSql(keytype2, keyval2))
                                .arg(conn->escapeIdentifier(keyname3))
                                .arg(conn->driver()->valueToSql(keytype3, keyval3)))
         : false;
 }
 
 bool KDb::deleteAllRecords(KDbConnection* conn, const QString &tableName)
 {
     return conn
         ? conn->executeSql(
               KDbEscapedString("DELETE FROM %1").arg(conn->escapeIdentifier(tableName)))
         : false;
 }
 
 KDB_EXPORT quint64 KDb::lastInsertedAutoIncValue(QSharedPointer<KDbSqlResult> result,
                                                  const QString &autoIncrementFieldName,
                                                  const QString &tableName, quint64 *recordId)
 {
     if (!result) {
         return std::numeric_limits<quint64>::max();
     }
     const quint64 foundRecordId = result->lastInsertRecordId();
     if (recordId) {
         *recordId = foundRecordId;
     }
     return KDb::lastInsertedAutoIncValue(result->connection(),
                                          foundRecordId, autoIncrementFieldName, tableName);
 }
 
 KDB_EXPORT quint64 KDb::lastInsertedAutoIncValue(KDbConnection *conn, const quint64 recordId,
                                                  const QString &autoIncrementFieldName,
                                                  const QString &tableName)
 {
     const KDbDriverBehavior *behavior = KDbDriverPrivate::behavior(conn->driver());
     if (behavior->ROW_ID_FIELD_RETURNS_LAST_AUTOINCREMENTED_VALUE) {
         return recordId;
     }
     KDbRecordData rdata;
     if (recordId == std::numeric_limits<quint64>::max()
         || true != conn->querySingleRecord(
                   KDbEscapedString("SELECT ") + escapeIdentifier(tableName) + '.'
                 + escapeIdentifier(autoIncrementFieldName)
                 + " FROM " + escapeIdentifier(tableName)
                 + " WHERE " + behavior->ROW_ID_FIELD_NAME
                 + '=' + KDbEscapedString::number(recordId), &rdata))
     {
         return std::numeric_limits<quint64>::max();
     }
     return rdata[0].toULongLong();
 }
 
 bool KDb::isEmptyValue(KDbField::Type type, const QVariant &value)
 {
     if (KDbField::isTextType(type)) {
         return value.toString().isEmpty() && !value.toString().isNull();
     }
     else if (type == KDbField::BLOB) {
         return value.toByteArray().isEmpty() && !value.toByteArray().isNull();
     }
     return value.isNull();
 }
 
 KDbEscapedString KDb::sqlWhere(KDbDriver *drv, KDbField::Type t,
                             const QString& fieldName, const QVariant& value)
 {
     if (value.isNull())
         return KDbEscapedString(fieldName) + " IS NULL";
     return KDbEscapedString(fieldName) + '=' + drv->valueToSql(t, value);
 }
 
 //! Cache
 struct TypeCache {
     TypeCache() {
         for (KDbField::Type t = KDbField::InvalidType; t <= KDbField::LastType; t = KDbField::Type(int(t) + 1)) {
             const KDbField::TypeGroup tg = KDbField::typeGroup(t);
             QList<KDbField::Type> list;
             QStringList name_list, str_list;
             if (tlist.contains(tg)) {
                 list = tlist.value(tg);
                 name_list = nlist.value(tg);
                 str_list = slist.value(tg);
             }
             list += t;
             name_list += KDbField::typeName(t);
             str_list += KDbField::typeString(t);
             tlist[ tg ] = list;
             nlist[ tg ] = name_list;
             slist[ tg ] = str_list;
         }
 
         def_tlist[ KDbField::InvalidGroup ] = KDbField::InvalidType;
         def_tlist[ KDbField::TextGroup ] = KDbField::Text;
         def_tlist[ KDbField::IntegerGroup ] = KDbField::Integer;
         def_tlist[ KDbField::FloatGroup ] = KDbField::Double;
         def_tlist[ KDbField::BooleanGroup ] = KDbField::Boolean;
         def_tlist[ KDbField::DateTimeGroup ] = KDbField::Date;
         def_tlist[ KDbField::BLOBGroup ] = KDbField::BLOB;
     }
 
     QHash< KDbField::TypeGroup, QList<KDbField::Type> > tlist;
     QHash< KDbField::TypeGroup, QStringList > nlist;
     QHash< KDbField::TypeGroup, QStringList > slist;
     QHash< KDbField::TypeGroup, KDbField::Type > def_tlist;
 };
 
 Q_GLOBAL_STATIC(TypeCache, KDb_typeCache)
 
 const QList<KDbField::Type> KDb::fieldTypesForGroup(KDbField::TypeGroup typeGroup)
 {
     return KDb_typeCache->tlist.value(typeGroup);
 }
 
 QStringList KDb::fieldTypeNamesForGroup(KDbField::TypeGroup typeGroup)
 {
     return KDb_typeCache->nlist.value(typeGroup);
 }
 
 QStringList KDb::fieldTypeStringsForGroup(KDbField::TypeGroup typeGroup)
 {
     return KDb_typeCache->slist.value(typeGroup);
 }
 
 KDbField::Type KDb::defaultFieldTypeForGroup(KDbField::TypeGroup typeGroup)
 {
     return (typeGroup <= KDbField::LastTypeGroup) ? KDb_typeCache->def_tlist.value(typeGroup) : KDbField::InvalidType;
 }
 
 void KDb::getHTMLErrorMesage(const KDbResultable& resultable, QString *msg, QString *details)
 {
     if (!msg) {
         kdbWarning() << "Missing 'msg' parameter";
         return;
     }
     if (!details) {
         kdbWarning() << "Missing 'details' parameter";
         return;
     }
     const KDbResult result(resultable.result());
     if (!result.isError())
         return;
     //lower level message is added to the details, if there is alread message specified
     if (!result.messageTitle().isEmpty())
         *msg += QLatin1String("<p>") + result.messageTitle();
 
     if (msg->isEmpty())
         *msg = QLatin1String("<p>") + result.message();
     else
         *details += QLatin1String("<p>") + result.message();
 
     if (!result.serverMessage().isEmpty())
         *details += QLatin1String("<p><b>") + kdb::tr("Message from server:")
                    + QLatin1String("</b> ") + result.serverMessage();
     if (!result.recentSqlString().isEmpty())
         *details += QLatin1String("<p><b>") + kdb::tr("SQL statement:")
                    + QString::fromLatin1("</b> <tt>%1</tt>").arg(result.recentSqlString().toString());
     int serverErrorCode = 0;
     QString serverResultName;
     if (result.isError()) {
         serverErrorCode = result.serverErrorCode();
         serverResultName = resultable.serverResultName();
     }
     if (   !details->isEmpty()
         && (   !result.serverMessage().isEmpty()
             || !result.recentSqlString().isEmpty()
             || !serverResultName.isEmpty()
             || serverErrorCode != 0)
            )
     {
         *details += (QLatin1String("<p><b>") + kdb::tr("Server result code:")
                     + QLatin1String("</b> ") + QString::number(serverErrorCode));
         if (!serverResultName.isEmpty()) {
             *details += QString::fromLatin1(" (%1)").arg(serverResultName);
         }
     }
     else {
         if (!serverResultName.isEmpty()) {
             *details += (QLatin1String("<p><b>") + kdb::tr("Server result:")
                         + QLatin1String("</b> ") + serverResultName);
         }
     }
 
     if (!details->isEmpty() && !details->startsWith(QLatin1String("<qt>"))) {
         if (!details->startsWith(QLatin1String("<p>")))
             details->prepend(QLatin1String("<p>"));
     }
 }
 
 void KDb::getHTMLErrorMesage(const KDbResultable& resultable, QString *msg)
 {
     getHTMLErrorMesage(resultable, msg, msg);
 }
 
 void KDb::getHTMLErrorMesage(const KDbResultable& resultable, KDbResultInfo *info)
 {
     if (!info) {
         kdbWarning() << "Missing 'info' parameter";
         return;
     }
     getHTMLErrorMesage(resultable, &info->message, &info->description);
 }
 
 tristate KDb::idForObjectName(KDbConnection* conn, int *id, const QString& objName, int objType)
 {
     return conn
         ? conn->querySingleNumber(
               KDbEscapedString("SELECT o_id FROM kexi__objects WHERE o_name=%1 AND o_type=%2")
                   .arg(conn->escapeString(objName))
                   .arg(objType),
               id)
         : false;
 }
 
 //-----------------------------------------
 
 tristate KDb::showConnectionTestDialog(QWidget *parent, const KDbConnectionData &data,
                                    KDbMessageHandler *msgHandler)
 {
     ConnectionTestDialog dlg(data, msgHandler, parent);
     const int result = dlg.exec();
     if (dlg.wasCanceled()) {
         return cancelled;
     }
     return result == QDialog::Accepted;
 }
 
 bool KDb::splitToTableAndFieldParts(const QString& string,
                                           QString *tableName, QString *fieldName,
                                           SplitToTableAndFieldPartsOptions option)
 {
     if (!tableName || !fieldName) {
         return false;
     }
     const int id = string.indexOf(QLatin1Char('.'));
     if (option & SetFieldNameIfNoTableName && id == -1) {
         tableName->clear();
         *fieldName = string;
         return !fieldName->isEmpty();
     }
     if (id <= 0 || id == int(string.length() - 1))
         return false;
     *tableName = string.left(id);
     *fieldName = string.mid(id + 1);
     return !tableName->isEmpty() && !fieldName->isEmpty();
 }
 
 bool KDb::supportsVisibleDecimalPlacesProperty(KDbField::Type type)
 {
 //! @todo add check for decimal type as well
     return KDbField::isFPNumericType(type);
 }
 
 inline static QString numberToString(double value, int decimalPlaces, const QLocale *locale)
 {
 //! @todo round?
     QString result;
     if (decimalPlaces == 0) {
         result = locale ? locale->toString(qlonglong(value))
                         : QString::number(qlonglong(value));
     } else {
         const int realDecimalPlaces = decimalPlaces < 0 ? 10 : decimalPlaces;
         result = locale ? locale->toString(value, 'f', realDecimalPlaces)
                         : QString::number(value, 'f', realDecimalPlaces);
         if (decimalPlaces < 0) { // cut off zeros
             int i = result.length() - 1;
             while (i > 0 && result[i] == QLatin1Char('0')) {
                 i--;
             }
             if (result[i].isDigit()) {// last digit
                 ++i;
             }
             result.truncate(i);
         }
     }
     return result;
 }
 
 QString KDb::numberToString(double value, int decimalPlaces)
 {
     return ::numberToString(value, decimalPlaces, nullptr);
 }
 
 QString KDb::numberToLocaleString(double value, int decimalPlaces)
 {
     QLocale defaultLocale;
     return ::numberToString(value, decimalPlaces, &defaultLocale);
 }
 
 QString KDb::numberToLocaleString(double value, int decimalPlaces, const QLocale &locale)
 {
     return ::numberToString(value, decimalPlaces, &locale);
 }
 
 KDbField::Type KDb::intToFieldType(int type)
 {
     if (type < int(KDbField::InvalidType) || type > int(KDbField::LastType)) {
         return KDbField::InvalidType;
     }
     return static_cast<KDbField::Type>(type);
 }
 
 KDbField::TypeGroup KDb::intToFieldTypeGroup(int typeGroup)
 {
     if (typeGroup < int(KDbField::InvalidGroup) || typeGroup > int(KDbField::LastTypeGroup)) {
         return KDbField::InvalidGroup;
     }
     return static_cast<KDbField::TypeGroup>(typeGroup);
 }
 
 static bool setIntToFieldType(KDbField *field, const QVariant& value)
 {
     Q_ASSERT(field);
     bool ok;
     const int intType = value.toInt(&ok);
     if (!ok) {//for sanity
         kdbWarning() << "Could not convert value" << value << "to field type";
         return false;
     }
     if (KDbField::InvalidType == KDb::intToFieldType(intType)) {//for sanity
         kdbWarning() << "Invalid field type" << intType;
         return false;
     }
     field->setType((KDbField::Type)intType);
     return true;
 }
 
 //! @internal for KDb::isBuiltinTableFieldProperty()
 struct KDb_BuiltinFieldProperties {
     KDb_BuiltinFieldProperties() {
 #define ADD(name) set.insert(name)
         ADD("type");
         ADD("primaryKey");
         ADD("indexed");
         ADD("autoIncrement");
         ADD("unique");
         ADD("notNull");
         ADD("allowEmpty");
         ADD("unsigned");
         ADD("name");
         ADD("caption");
         ADD("description");
         ADD("maxLength");
         ADD("maxLengthIsDefault");
         ADD("precision");
         ADD("defaultValue");
         ADD("defaultWidth");
         ADD("visibleDecimalPlaces");
 //! @todo always update this when new builtins appear!
 #undef ADD
     }
     QSet<QByteArray> set;
 };
 
 //! for KDb::isBuiltinTableFieldProperty()
 Q_GLOBAL_STATIC(KDb_BuiltinFieldProperties, KDb_builtinFieldProperties)
 
 
 bool KDb::isBuiltinTableFieldProperty(const QByteArray& propertyName)
 {
     return KDb_builtinFieldProperties->set.contains(propertyName);
 }
 
 static QVariant visibleColumnValue(const KDbLookupFieldSchema *lookup)
 {
     if (!lookup || lookup->visibleColumns().count() == 1) {
         if (lookup) {
             const QList<int> visibleColumns = lookup->visibleColumns();
             if (!visibleColumns.isEmpty()) {
                 return visibleColumns.first();
             }
         }
         return QVariant();
     }
     QList<QVariant> variantList;
     const QList<int> visibleColumns(lookup->visibleColumns());
     for(int column : visibleColumns) {
         variantList.append(column);
     }
     return variantList;
 }
 
 void KDb::getProperties(const KDbLookupFieldSchema *lookup, QMap<QByteArray, QVariant> *values)
 {
     if (!values) {
         return;
     }
     KDbLookupFieldSchemaRecordSource recordSource;
     if (lookup) {
         recordSource = lookup->recordSource();
     }
     values->insert("rowSource", lookup ? recordSource.name() : QVariant());
     values->insert("rowSourceType", lookup ? recordSource.typeName() : QVariant());
     values->insert("rowSourceValues",
         (lookup && !recordSource.values().isEmpty()) ? recordSource.values() : QVariant());
     values->insert("boundColumn", lookup ? lookup->boundColumn() : QVariant());
     values->insert("visibleColumn", visibleColumnValue(lookup));
    QList<QVariant> variantList;
     if (lookup) {
         const QList<int> columnWidths = lookup->columnWidths();
         for(const QVariant& variant : columnWidths) {
             variantList.append(variant);
         }
     }
     values->insert("columnWidths", lookup ? variantList : QVariant());
     values->insert("showColumnHeaders", lookup ? lookup->columnHeadersVisible() : QVariant());
     values->insert("listRows", lookup ? lookup->maxVisibleRecords() : QVariant());
     values->insert("limitToList", lookup ? lookup->limitToList() : QVariant());
     values->insert("displayWidget", lookup ? int(lookup->displayWidget()) : QVariant());
 }
 
 void KDb::getFieldProperties(const KDbField &field, QMap<QByteArray, QVariant> *values)
 {
     if (!values) {
         return;
     }
     values->clear();
     // normal values
     values->insert("type", field.type());
     const KDbField::Constraints constraints = field.constraints();
     values->insert("primaryKey", constraints.testFlag(KDbField::PrimaryKey));
     values->insert("indexed", constraints.testFlag(KDbField::Indexed));
     values->insert("autoIncrement", KDbField::isAutoIncrementAllowed(field.type())
                                     && constraints.testFlag(KDbField::AutoInc));
     values->insert("unique", constraints.testFlag(KDbField::Unique));
     values->insert("notNull", constraints.testFlag(KDbField::NotNull));
     values->insert("allowEmpty", !constraints.testFlag(KDbField::NotEmpty));
     const KDbField::Options options = field.options();
     values->insert("unsigned", options.testFlag(KDbField::Unsigned));
     values->insert("name", field.name());
     values->insert("caption", field.caption());
     values->insert("description", field.description());
     values->insert("maxLength", field.maxLength());
     values->insert("maxLengthIsDefault", field.maxLengthStrategy() & KDbField::DefaultMaxLength);
     values->insert("precision", field.precision());
     values->insert("defaultValue", field.defaultValue());
 //! @todo IMPORTANT: values->insert("defaultWidth", field.defaultWidth());
     if (KDb::supportsVisibleDecimalPlacesProperty(field.type())) {
         values->insert("visibleDecimalPlaces", field.defaultValue());
     }
     // insert lookup-related values
     const KDbLookupFieldSchema *lookup = field.table()->lookupFieldSchema(field);
     KDb::getProperties(lookup, values);
 }
 
 static bool containsLookupFieldSchemaProperties(const QMap<QByteArray, QVariant>& values)
 {
     for (QMap<QByteArray, QVariant>::ConstIterator it(values.constBegin());
          it != values.constEnd(); ++it)
     {
         if (KDb::isLookupFieldSchemaProperty(it.key())) {
             return true;
         }
     }
     return false;
 }
 
 bool KDb::setFieldProperties(KDbField *field, const QMap<QByteArray, QVariant>& values)
 {
     if (!field) {
         return false;
     }
     QMap<QByteArray, QVariant>::ConstIterator it;
     if ((it = values.find("type")) != values.constEnd()) {
         if (!setIntToFieldType(field, *it))
             return false;
     }
 
 #define SET_BOOLEAN_FLAG(flag, value) { \
         constraints |= KDbField::flag; \
         if (!value) \
             constraints ^= KDbField::flag; \
     }
 
     KDbField::Constraints constraints = field->constraints();
     bool ok = true;
     if ((it = values.find("primaryKey")) != values.constEnd())
         SET_BOOLEAN_FLAG(PrimaryKey, (*it).toBool());
     if ((it = values.find("indexed")) != values.constEnd())
         SET_BOOLEAN_FLAG(Indexed, (*it).toBool());
     if ((it = values.find("autoIncrement")) != values.constEnd()
             && KDbField::isAutoIncrementAllowed(field->type()))
         SET_BOOLEAN_FLAG(AutoInc, (*it).toBool());
     if ((it = values.find("unique")) != values.constEnd())
         SET_BOOLEAN_FLAG(Unique, (*it).toBool());
     if ((it = values.find("notNull")) != values.constEnd())
         SET_BOOLEAN_FLAG(NotNull, (*it).toBool());
     if ((it = values.find("allowEmpty")) != values.constEnd())
         SET_BOOLEAN_FLAG(NotEmpty, !(*it).toBool());
     field->setConstraints(constraints);
 
     KDbField::Options options;
     if ((it = values.find("unsigned")) != values.constEnd()) {
         options |= KDbField::Unsigned;
         if (!(*it).toBool())
             options ^= KDbField::Unsigned;
     }
     field->setOptions(options);
 
     if ((it = values.find("name")) != values.constEnd())
         field->setName((*it).toString());
     if ((it = values.find("caption")) != values.constEnd())
         field->setCaption((*it).toString());
     if ((it = values.find("description")) != values.constEnd())
         field->setDescription((*it).toString());
     if ((it = values.find("maxLength")) != values.constEnd())
         field->setMaxLength((*it).isNull() ? 0/*default*/ : (*it).toInt(&ok));
     if (!ok)
         return false;
     if ((it = values.find("maxLengthIsDefault")) != values.constEnd()
             && (*it).toBool())
     {
         field->setMaxLengthStrategy(KDbField::DefaultMaxLength);
     }
     if ((it = values.find("precision")) != values.constEnd())
         field->setPrecision((*it).isNull() ? 0/*default*/ : (*it).toInt(&ok));
     if (!ok)
         return false;
     if ((it = values.find("defaultValue")) != values.constEnd())
         field->setDefaultValue(*it);
 //! @todo IMPORTANT: defaultWidth
 #if 0
     if ((it = values.find("defaultWidth")) != values.constEnd())
         field.setDefaultWidth((*it).isNull() ? 0/*default*/ : (*it).toInt(&ok));
     if (!ok)
         return false;
 #endif
 
     // -- extended properties
     if ((it = values.find("visibleDecimalPlaces")) != values.constEnd()
             && KDb::supportsVisibleDecimalPlacesProperty(field->type()))
         field->setVisibleDecimalPlaces((*it).isNull() ? -1/*default*/ : (*it).toInt(&ok));
     if (!ok)
         return false;
 
     if (field->table() && containsLookupFieldSchemaProperties(values)) {
         KDbLookupFieldSchema *lookup = field->table()->lookupFieldSchema(*field);
         QScopedPointer<KDbLookupFieldSchema> createdLookup;
         if (!lookup) { // create lookup if needed
             createdLookup.reset(lookup = new KDbLookupFieldSchema());
         }
         if (lookup->setProperties(values)) {
             if (createdLookup) {
                 if (field->table()->setLookupFieldSchema(field->name(), lookup)) {
                     createdLookup.take(); // ownership passed
                     lookup = nullptr;
                 }
             }
         }
     }
 
     return true;
 #undef SET_BOOLEAN_FLAG
 }
 
 //! @internal for isExtendedTableProperty()
 struct KDb_ExtendedProperties {
     KDb_ExtendedProperties() {
 #define ADD(name) set.insert( name )
         ADD("visibledecimalplaces");
         ADD("rowsource");
         ADD("rowsourcetype");
         ADD("rowsourcevalues");
         ADD("boundcolumn");
         ADD("visiblecolumn");
         ADD("columnwidths");
         ADD("showcolumnheaders");
         ADD("listrows");
         ADD("limittolist");
         ADD("displaywidget");
 #undef ADD
     }
     QSet<QByteArray> set;
 };
 
 //! for isExtendedTableProperty()
 Q_GLOBAL_STATIC(KDb_ExtendedProperties, KDb_extendedProperties)
 
 bool KDb::isExtendedTableFieldProperty(const QByteArray& propertyName)
 {
     return KDb_extendedProperties->set.contains(QByteArray(propertyName).toLower());
 }
 
 //! @internal for isLookupFieldSchemaProperty()
 struct KDb_LookupFieldSchemaProperties {
     KDb_LookupFieldSchemaProperties() {
         QMap<QByteArray, QVariant> tmp;
         KDb::getProperties(nullptr, &tmp);
         for (QMap<QByteArray, QVariant>::ConstIterator it(tmp.constBegin());
              it != tmp.constEnd(); ++it)
         {
             set.insert(it.key().toLower());
         }
     }
     QSet<QByteArray> set;
 };
 
 //! for isLookupFieldSchemaProperty()
 Q_GLOBAL_STATIC(KDb_LookupFieldSchemaProperties, KDb_lookupFieldSchemaProperties)
 
 bool KDb::isLookupFieldSchemaProperty(const QByteArray& propertyName)
 {
     return KDb_lookupFieldSchemaProperties->set.contains(propertyName.toLower());
 }
 
 bool KDb::setFieldProperty(KDbField *field, const QByteArray& propertyName, const QVariant& value)
 {
     if (!field) {
         return false;
     }
 #define SET_BOOLEAN_FLAG(flag, value) { \
         constraints |= KDbField::flag; \
         if (!value) \
             constraints ^= KDbField::flag; \
         field->setConstraints( constraints ); \
         return true; \
     }
 #define GET_INT(method) { \
         const int ival = value.toInt(&ok); \
         if (!ok) \
             return false; \
         field->method( ival ); \
         return true; \
     }
 
     if (propertyName.isEmpty())
         return false;
 
     bool ok;
     if (KDb::isExtendedTableFieldProperty(propertyName)) {
         //a little speedup: identify extended property in O(1)
         if ("visibleDecimalPlaces" == propertyName
                 && KDb::supportsVisibleDecimalPlacesProperty(field->type())) {
             GET_INT(setVisibleDecimalPlaces);
         }
         else if (KDb::isLookupFieldSchemaProperty(propertyName)) {
             if (!field->table()) {
                 kdbWarning() << "Could not set" << propertyName << "property - no table assigned for field";
             } else {
                 KDbLookupFieldSchema *lookup = field->table()->lookupFieldSchema(*field);
                 const bool createLookup = !lookup;
                 if (createLookup) // create lookup if needed
                     lookup = new KDbLookupFieldSchema();
                 if (lookup->setProperty(propertyName, value)) {
                     if (createLookup)
                         field->table()->setLookupFieldSchema(field->name(), lookup);
                     return true;
                 }
                 if (createLookup)
                     delete lookup; // not set, delete
             }
         }
     } else {//non-extended
         if ("type" == propertyName)
             return setIntToFieldType(field, value);
 
         KDbField::Constraints constraints = field->constraints();
         if ("primaryKey" == propertyName)
             SET_BOOLEAN_FLAG(PrimaryKey, value.toBool());
         if ("indexed" == propertyName)
             SET_BOOLEAN_FLAG(Indexed, value.toBool());
         if ("autoIncrement" == propertyName
                 && KDbField::isAutoIncrementAllowed(field->type()))
             SET_BOOLEAN_FLAG(AutoInc, value.toBool());
         if ("unique" == propertyName)
             SET_BOOLEAN_FLAG(Unique, value.toBool());
         if ("notNull" == propertyName)
             SET_BOOLEAN_FLAG(NotNull, value.toBool());
         if ("allowEmpty" == propertyName)
             SET_BOOLEAN_FLAG(NotEmpty, !value.toBool());
 
         KDbField::Options options;
         if ("unsigned" == propertyName) {
             options |= KDbField::Unsigned;
             if (!value.toBool())
                 options ^= KDbField::Unsigned;
             field->setOptions(options);
             return true;
         }
 
         if ("name" == propertyName) {
             if (value.toString().isEmpty())
                 return false;
             field->setName(value.toString());
             return true;
         }
         if ("caption" == propertyName) {
             field->setCaption(value.toString());
             return true;
         }
         if ("description" == propertyName) {
             field->setDescription(value.toString());
             return true;
         }
         if ("maxLength" == propertyName)
             GET_INT(setMaxLength);
         if ("maxLengthIsDefault" == propertyName) {
             field->setMaxLengthStrategy(KDbField::DefaultMaxLength);
         }
         if ("precision" == propertyName)
             GET_INT(setPrecision);
         if ("defaultValue" == propertyName) {
             field->setDefaultValue(value);
             return true;
         }
 
 //! @todo IMPORTANT: defaultWidth
 #if 0
         if ("defaultWidth" == propertyName)
             GET_INT(setDefaultWidth);
 #endif
         // last chance that never fails: custom field property
         field->setCustomProperty(propertyName, value);
     }
 
     kdbWarning() << "Field property" << propertyName << "not found!";
     return false;
 #undef SET_BOOLEAN_FLAG
 #undef GET_INT
 }
 
 int KDb::loadIntPropertyValueFromDom(const QDomNode& node, bool* ok)
 {
     QByteArray valueType = node.nodeName().toLatin1();
     if (valueType.isEmpty() || valueType != "number") {
         if (ok)
             *ok = false;
         return 0;
     }
     const QString text(QDomNode(node).toElement().text());
     int val = text.toInt(ok);
     return val;
 }
 
 QString KDb::loadStringPropertyValueFromDom(const QDomNode& node, bool* ok)
 {
     QByteArray valueType = node.nodeName().toLatin1();
     if (valueType != "string") {
         if (ok)
             *ok = false;
         return QString();
     }
     if (ok)
         *ok = true;
     return QDomNode(node).toElement().text();
 }
 
 QVariant KDb::loadPropertyValueFromDom(const QDomNode& node, bool* ok)
 {
     QByteArray valueType = node.nodeName().toLatin1();
     if (valueType.isEmpty()) {
         if (ok)
             *ok = false;
         return QVariant();
     }
     if (ok)
         *ok = true;
     const QString text(QDomNode(node).toElement().text());
     bool _ok;
     if (valueType == "string") {
         return text;
     }
     else if (valueType == "cstring") {
         return text.toLatin1();
     }
     else if (valueType == "number") { // integer or double
         if (text.indexOf(QLatin1Char('.')) != -1) {
             double val = text.toDouble(&_ok);
             if (_ok)
                 return val;
         }
         else {
             const int val = text.toInt(&_ok);
             if (_ok)
                 return val;
             const qint64 valLong = text.toLongLong(&_ok);
             if (_ok)
                 return valLong;
         }
     }
     else if (valueType == "bool") {
         return text.compare(QLatin1String("true"), Qt::CaseInsensitive) == 0
                || text == QLatin1String("1");
     }
     else {
 //! @todo add more QVariant types
         kdbWarning() << "Unknown property type" << valueType;
     }
     if (ok)
         *ok = false;
     return QVariant();
 }
 
 QDomElement KDb::saveNumberElementToDom(QDomDocument *doc, QDomElement *parentEl,
         const QString& elementName, int value)
 {
     if (!doc || !parentEl || elementName.isEmpty()) {
         return QDomElement();
     }
     QDomElement el(doc->createElement(elementName));
     parentEl->appendChild(el);
     QDomElement numberEl(doc->createElement(QLatin1String("number")));
     el.appendChild(numberEl);
     numberEl.appendChild(doc->createTextNode(QString::number(value)));
     return el;
 }
 
 QDomElement KDb::saveBooleanElementToDom(QDomDocument *doc, QDomElement *parentEl,
         const QString& elementName, bool value)
 {
     if (!doc || !parentEl || elementName.isEmpty()) {
         return QDomElement();
     }
     QDomElement el(doc->createElement(elementName));
     parentEl->appendChild(el);
     QDomElement numberEl(doc->createElement(QLatin1String("bool")));
     el.appendChild(numberEl);
     numberEl.appendChild(doc->createTextNode(
                              value ? QLatin1String("true") : QLatin1String("false")));
     return el;
 }
 
 //! @internal Used in KDb::emptyValueForFieldType()
 struct KDb_EmptyValueForFieldTypeCache {
     KDb_EmptyValueForFieldTypeCache()
             : values(int(KDbField::LastType) + 1) {
 #define ADD(t, value) values.insert(t, value);
         ADD(KDbField::Byte, 0);
         ADD(KDbField::ShortInteger, 0);
         ADD(KDbField::Integer, 0);
         ADD(KDbField::BigInteger, 0);
         ADD(KDbField::Boolean, false);
         ADD(KDbField::Float, 0.0);
         ADD(KDbField::Double, 0.0);
 //! @todo ok? we have no better defaults
         ADD(KDbField::Text, QLatin1String(" "));
         ADD(KDbField::LongText, QLatin1String(" "));
         ADD(KDbField::BLOB, QByteArray());
 #undef ADD
     }
     QVector<QVariant> values;
 };
 
 //! Used in KDb::emptyValueForFieldType()
 Q_GLOBAL_STATIC(KDb_EmptyValueForFieldTypeCache, KDb_emptyValueForFieldTypeCache)
 
 QVariant KDb::emptyValueForFieldType(KDbField::Type type)
 {
     const QVariant val(KDb_emptyValueForFieldTypeCache->values.at(
                            (type <= KDbField::LastType) ? type : KDbField::InvalidType));
     if (!val.isNull())
         return val;
     else { //special cases
         if (type == KDbField::Date)
             return QDate::currentDate();
         if (type == KDbField::DateTime)
             return QDateTime::currentDateTime();
         if (type == KDbField::Time)
             return QTime::currentTime();
     }
     kdbWarning() << "No empty value for field type" << KDbField::typeName(type);
     return QVariant();
 }
 
 //! @internal Used in KDb::notEmptyValueForFieldType()
 struct KDb_NotEmptyValueForFieldTypeCache {
     KDb_NotEmptyValueForFieldTypeCache()
             : values(int(KDbField::LastType) + 1) {
 #define ADD(t, value) values.insert(t, value);
         // copy most of the values
         for (int i = int(KDbField::InvalidType) + 1; i <= KDbField::LastType; i++) {
             if (i == KDbField::Date || i == KDbField::DateTime || i == KDbField::Time)
                 continue; //'current' value will be returned
             if (i == KDbField::Text || i == KDbField::LongText) {
                 ADD(i, QVariant(QLatin1String("")));
                 continue;
             }
             if (i == KDbField::BLOB) {
 //! @todo blobs will contain other MIME types too
                 QByteArray ba;
 //! @todo port to Qt4
 #if 0
                 QBuffer buffer(&ba);
                 buffer.open(QIODevice::WriteOnly);
                 QPixmap pm(SmallIcon("document-new"));
                 pm.save(&buffer, "PNG"/*! @todo default? */);
 #endif
                 ADD(i, ba);
                 continue;
             }
             ADD(i, KDb::emptyValueForFieldType((KDbField::Type)i));
         }
 #undef ADD
     }
     QVector<QVariant> values;
 };
 //! Used in KDb::notEmptyValueForFieldType()
 Q_GLOBAL_STATIC(KDb_NotEmptyValueForFieldTypeCache, KDb_notEmptyValueForFieldTypeCache)
 
 QVariant KDb::notEmptyValueForFieldType(KDbField::Type type)
 {
     const QVariant val(KDb_notEmptyValueForFieldTypeCache->values.at(
                            (type <= KDbField::LastType) ? type : KDbField::InvalidType));
     if (!val.isNull())
         return val;
     else { //special cases
         if (type == KDbField::Date)
             return QDate::currentDate();
         if (type == KDbField::DateTime)
             return QDateTime::currentDateTime();
         if (type == KDbField::Time)
             return QTime::currentTime();
     }
     kdbWarning() << "No non-empty value for field type" << KDbField::typeName(type);
     return QVariant();
 }
 
 //! @internal @return nestimated new length after escaping of string @a string
 template<typename T>
 inline static int estimatedNewLength(const T &string, bool addQuotes)
 {
     if (string.length() < 10)
         return string.length() * 2 + (addQuotes ? 2 : 0);
     return string.length() * 3 / 2;
 }
 
 //! @internal @return @a string string with applied KDbSQL identifier escaping.
 //! If @a addQuotes is true, '"' characer is prepended and appended.
 template<typename T, typename Latin1StringType, typename Latin1CharType, typename CharType>
 inline static T escapeIdentifier(const T& string, bool addQuotes)
 {
     const Latin1CharType quote('"');
     // create
     Latin1StringType escapedQuote("\"\"");
     T newString;
     newString.reserve(estimatedNewLength(string, addQuotes));
     if (addQuotes) {
         newString.append(quote);
     }
     for (int i = 0; i < string.length(); i++) {
         const CharType c = string.at(i);
         if (c == quote)
             newString.append(escapedQuote);
         else
             newString.append(c);
     }
     if (addQuotes) {
         newString.append(quote);
     }
     newString.squeeze();
     return newString;
 }
 
 static bool shouldAddQuotesToIdentifier(const QByteArray& string)
 {
     return !string.isEmpty() && (!KDb::isIdentifier(string) || KDb::isKDbSqlKeyword(string));
 }
 
 QString KDb::escapeIdentifier(const QString& string)
 {
     return ::escapeIdentifier<QString, QLatin1String, QLatin1Char, QChar>(
         string, shouldAddQuotesToIdentifier(string.toLatin1()));
 }
 
 QByteArray KDb::escapeIdentifier(const QByteArray& string)
 {
     return ::escapeIdentifier<QByteArray, QByteArray, char, char>(
         string, shouldAddQuotesToIdentifier(string));
 }
 
 QString KDb::escapeIdentifierAndAddQuotes(const QString& string)
 {
     return ::escapeIdentifier<QString, QLatin1String, QLatin1Char, QChar>(string, true);
 }
 
 QByteArray KDb::escapeIdentifierAndAddQuotes(const QByteArray& string)
 {
     return ::escapeIdentifier<QByteArray, QByteArray, char, char>(string, true);
 }
 
 QString KDb::escapeString(const QString& string)
 {
     const QLatin1Char quote('\'');
     // find out the length ot the destination string
     // create
     QString newString(quote);
     newString.reserve(estimatedNewLength(string, true));
     for (int i = 0; i < string.length(); i++) {
         const QChar c = string.at(i);
         const ushort unicode = c.unicode();
         if (unicode == quote)
             newString.append(QLatin1String("''"));
         else if (unicode == '\t')
             newString.append(QLatin1String("\\t"));
         else if (unicode == '\\')
             newString.append(QLatin1String("\\\\"));
         else if (unicode == '\n')
             newString.append(QLatin1String("\\n"));
         else if (unicode == '\r')
             newString.append(QLatin1String("\\r"));
         else if (unicode == '\0')
             newString.append(QLatin1String("\\0"));
         else
             newString.append(c);
     }
     newString.append(QLatin1Char(quote));
     return newString;
 }
 
 KDbEscapedString KDb::escapeString(KDbDriver *drv, const QString& string)
 {
     return drv ? drv->escapeString(string) : KDbEscapedString(KDb::escapeString(string));
 }
 
 KDbEscapedString KDb::escapeString(KDbConnection *conn, const QString& string)
 {
     return conn ? conn->escapeString(string) : KDbEscapedString(KDb::escapeString(string));
 }
 
 //! @see handleHex()
 const int CODE_POINT_DIGITS = std::numeric_limits<int>::max();
 //! @see handleHex()
 const int MAX_CODE_POINT_VALUE = 0x10FFFF;
 
 //! @internal Decodes hex of length @a digits for handleXhh(), handleUxxxx() and handleUcodePoint()
 //! If @a digits is CODE_POINT_DIGITS, any number of hex digits is decoded until '}' character
 //! is found (error if not found), and the function succeeds when the resulting number
 //! is not larger than MAX_CODE_POINT_VALUE.
 //! If @a digits is smaller than CODE_POINT_DIGITS the function succeeds only if exactly @a digits
 //! number of digits has been found.
 //! @return -1 on error (when invalid character found or on missing character
 //! or if the resulting number is too large)
 //! @see KDb::unescapeString()
 static int handleHex(QString *result, int *from, int stringLen, int *errorPosition, int digits)
 {
     int digit = 0;
     for (int i=0; i<digits; ++i) {
         if ((*from + 1) >=  stringLen) { // unfinished
             if (errorPosition) {
                 *errorPosition = *from;
             }
             return -1;
         }
         ++(*from);
         if (digits == CODE_POINT_DIGITS && (*result)[*from] == QLatin1Char('}')) {
             // special case: code point character decoded
             if (i == 0) {
                 if (errorPosition) {
                     *errorPosition = *from;
                 }
                 return -1;
             }
             return digit;
         }
         const unsigned char d = hexDigitToInt((*result)[*from].toLatin1());
         if (d == 0xFF) { // unfinished or wrong character
             if (errorPosition) {
                 *errorPosition = *from;
             }
             return -1;
         }
         digit = (digit << 4) + d;
         if (digits == CODE_POINT_DIGITS) {
             if (digit > MAX_CODE_POINT_VALUE) { // special case: exceeded limit of code point
                 if (errorPosition) {
                     *errorPosition = *from;
                 }
                 return -1;
             }
         }
     }
     return digit;
 }
 
 //! @internal Handles \xhh format for handleEscape()
 //! Assumption: the @a *from points to "x" in the "\x"
 //! @see KDb::unescapeString()
 static bool handleXhh(QString *result, int *from, int to, int stringLen, int *errorPosition)
 {
     const int intDigit = handleHex(result, from, stringLen, errorPosition, 2);
     if (intDigit == -1) {
         return false;
     }
     (*result)[to] = QChar(static_cast<unsigned char>(intDigit), 0);
     return true;
 }
 
 //! @internal Handles \uxxxx format for handleEscape()
 //! Assumption: the @a *from points to the "u" in the "\u".
 //! @see KDb::unescapeString()
 static bool handleUxxxx(QString *result, int *from, int to, int stringLen, int *errorPosition)
 {
     const int intDigit = handleHex(result, from, stringLen, errorPosition, 4);
     if (intDigit == -1) {
         return false;
     }
     (*result)[to] = QChar(static_cast<unsigned short>(intDigit));
     return true;
 }
 
 //! @internal Handles \u{xxxxxx} format for handleEscape()
 //! Assumption: the @a *from points to the "{" in the "\u{".
 //! @see KDb::unescapeString()
 static bool handleUcodePoint(QString *result, int *from, int to, int stringLen, int *errorPosition)
 {
     const int intDigit = handleHex(result, from, stringLen, errorPosition, CODE_POINT_DIGITS);
     if (intDigit == -1) {
         return false;
     }
     (*result)[to] = QChar(intDigit);
     return true;
 }
 
 //! @internal Handles escaped character @a c2 for KDb::unescapeString()
 //! Updates @a result
 //! @return true on success
 static bool handleEscape(QString *result, int *from, int *to, int stringLen, int *errorPosition)
 {
     const QCharRef c2 = (*result)[*from];
     if (c2 == QLatin1Char('x')) { // \xhh
         if (!handleXhh(result, from, *to, stringLen, errorPosition)) {
             return false;
         }
     } else if (c2 == QLatin1Char('u')) { // \u
         if ((*from + 1) >=  stringLen) { // unfinished
             if (errorPosition) {
                 *errorPosition = *from;
             }
             return false;
         }
         ++(*from);
         const QCharRef c3 = (*result)[*from];
         if (c3 == QLatin1Char('{')) { // \u{
             if (!handleUcodePoint(result, from, *to, stringLen, errorPosition)) {
                 return false;
             }
         } else {
             --(*from);
             if (!handleUxxxx(result, from, *to, stringLen, errorPosition)) {
                 return false;
             }
         }
 #define _RULE(in, out) \
     } else if (c2 == QLatin1Char(in)) { \
         (*result)[*to] = QLatin1Char(out);
     _RULE('0', '\0') _RULE('b', '\b') _RULE('f', '\f') _RULE('n', '\n')
     _RULE('r', '\r') _RULE('t', '\t') _RULE('v', '\v')
 #undef _RULE
     } else { // \ ' " ? % _ and any other without special meaning can be escaped: just skip "\"
         (*result)[*to] = c2;
     }
     return true;
 }
 
 QString KDb::unescapeString(const QString& string, char quote, int *errorPosition)
 {
     if (quote != '\'' && quote != '\"') {
         if (errorPosition) {
             *errorPosition = 0;
         }
         return QString();
     }
     const QLatin1Char quoteChar(quote);
     if (string.isEmpty()
         || (!string.contains(QLatin1Char('\\')) && !string.contains(quoteChar)))
     {
         if (errorPosition) {
             *errorPosition = -1;
         }
         return string; // optimization: there are no escapes and quotes
     }
     QString result(string);
     const int stringLen = string.length();
     int from = 0;
     int to = 0;
     bool doubleQuoteExpected = false;
     while (from < stringLen) {
         const QCharRef c = result[from];
         if (doubleQuoteExpected) {
             if (c == quoteChar) {
                 result[to] = c;
                 doubleQuoteExpected = false;
             } else {
                 // error: missing second quote
                 if (errorPosition) {
                     *errorPosition = from - 1; // -1 because error is at prev. char
                 }
                 return QString();
             }
         } else if (c == quoteChar) {
             doubleQuoteExpected = true;
             ++from;
             continue;
         } else if (c == QLatin1Char('\\')) { // escaping
             if ((from + 1) >=  stringLen) { // ignore unfinished '\'
                 break;
             }
             ++from;
             if (!handleEscape(&result, &from, &to, stringLen, errorPosition)) {
                 return QString();
             }
         } else { // normal character: skip
             result[to] = result[from];
         }
         ++from;
         ++to;
     }
     if (doubleQuoteExpected) { // error: string ends with a single quote
         if (errorPosition) {
             *errorPosition = from - 1;
         }
         return QString();
     }
     if (errorPosition) {
         *errorPosition = -1;
     }
     result.truncate(to);
     return result;
 }
 
 //! @return hex digit '0'..'F' for integer number 0..15
 inline static char intToHexDigit(unsigned char val)
 {
     return (val < 10) ? ('0' + val) : ('A' + (val - 10));
 }
 
 QString KDb::escapeBLOB(const QByteArray& array, BLOBEscapingType type)
 {
     const int size = array.size();
     if (size == 0 && type == BLOBEscapingType::ZeroXHex)
         return QString();
     int escaped_length = size * 2;
     if (type == BLOBEscapingType::ZeroXHex || type == BLOBEscapingType::Octal)
         escaped_length += 2/*0x or X'*/;
     else if (type == BLOBEscapingType::XHex)
         escaped_length += 3; //X' + '
     else if (type == BLOBEscapingType::ByteaHex)
         escaped_length += (4 + 8); // E'\x + '::bytea
 
     QString str;
     str.reserve(escaped_length);
     if (str.capacity() < escaped_length) {
         kdbWarning() << "Not enough memory (cannot allocate" << escaped_length << "characters)";
         return QString();
     }
     if (type == BLOBEscapingType::XHex)
         str = QString::fromLatin1("X'");
     else if (type == BLOBEscapingType::ZeroXHex)
         str = QString::fromLatin1("0x");
     else if (type == BLOBEscapingType::Octal)
         str = QString::fromLatin1("'");
     else if (type == BLOBEscapingType::ByteaHex)
         str = QString::fromLatin1("E'\\\\x");
 
     int new_length = str.length(); //after X' or 0x, etc.
     if (type == BLOBEscapingType::Octal) {
         // only escape nonprintable characters as in Table 8-7:
         // https://www.postgresql.org/docs/8.1/interactive/datatype-binary.html
         // i.e. escape for bytes: < 32, >= 127, 39 ('), 92(\).
         for (int i = 0; i < size; i++) {
             const unsigned char val = array[i];
             if (val < 32 || val >= 127 || val == 39 || val == 92) {
                 str[new_length++] = '\\';
                 str[new_length++] = '\\';
                 str[new_length++] = '0' + val / 64;
                 str[new_length++] = '0' + (val % 64) / 8;
                 str[new_length++] = '0' + val % 8;
             } else {
                 str[new_length++] = val;
             }
         }
     } else {
         for (int i = 0; i < size; i++) {
             const unsigned char val = array[i];
             str[new_length++] = intToHexDigit(val / 16);
             str[new_length++] = intToHexDigit(val % 16);
         }
     }
     if (type == BLOBEscapingType::XHex || type == BLOBEscapingType::Octal) {
         str[new_length++] = '\'';
     } else if (type == BLOBEscapingType::ByteaHex) {
         str[new_length++] = '\'';
         str[new_length++] = ':';
         str[new_length++] = ':';
         str[new_length++] = 'b';
         str[new_length++] = 'y';
         str[new_length++] = 't';
         str[new_length++] = 'e';
         str[new_length++] = 'a';
     }
     return str;
 }
 
 QByteArray KDb::pgsqlByteaToByteArray(const char* data, int length)
 {
     if (!data) {
         return QByteArray();
     }
     QByteArray array;
     int output = 0;
     if (length < 0) {
         length = qstrlen(data);
     }
     for (int pass = 0; pass < 2; pass++) {//2 passes to avoid allocating buffer twice:
         //  0: count #of chars; 1: copy data
         const char* s = data;
         const char* end = s + length;
         if (pass == 1) {
             //kdbDebug() << "processBinaryData(): real size == " << output;
             array.resize(output);
             output = 0;
         }
         for (int input = 0; s < end; output++) {
             //  kdbDebug()<<(int)s[0]<<" "<<(int)s[1]<<" "<<(int)s[2]<<" "<<(int)s[3]<<" "<<(int)s[4];
             if (s[0] == '\\' && (s + 1) < end) {
                 //special cases as in https://www.postgresql.org/docs/8.1/interactive/datatype-binary.html
                 if (s[1] == '\'') {// \'
                     if (pass == 1)
                         array[output] = '\'';
                     s += 2;
                 } else if (s[1] == '\\') { // 2 backslashes
                     if (pass == 1)
                         array[output] = '\\';
                     s += 2;
                 } else if ((input + 3) < length) {// \\xyz where xyz are 3 octal digits
                     if (pass == 1)
                         array[output] = char((int(s[1] - '0') * 8 + int(s[2] - '0')) * 8 + int(s[3] - '0'));
                     s += 4;
                 } else {
                     kdbWarning() << "Missing octal value after backslash";
                     s++;
                 }
             } else {
                 if (pass == 1)
                     array[output] = s[0];
                 s++;
             }
             //  kdbDebug()<<output<<": "<<(int)array[output];
         }
     }
     return array;
 }
 
 QByteArray KDb::xHexToByteArray(const char* data, int length, bool *ok)
 {
     if (length < 0) {
         length = qstrlen(data);
     }
     if (length < 3 || data[0] != 'X' || data[1] != '\'' || data[length-1] != '\'') { // must be at least X''
         if (ok) {
             *ok = false;
         }
         return QByteArray();
     }
     data += 2; // eat X'
     length -= 3; // eax X' and '
     QByteArray array;
     if (!hexToByteArrayInternal(data, length, &array)) {
         if (ok) {
             *ok = false;
         }
         array.clear();
     }
     if (ok) {
         *ok = true;
     }
     return array;
 }
 
 /*! \return byte array converted from \a data of length \a length.
  \a data is escaped in format 0x*, where * is one or more bytes in hexadecimal format.
  See BLOBEscapingType::ZeroXHex. */
 QByteArray KDb::zeroXHexToByteArray(const char* data, int length, bool *ok)
 {
     if (length < 0) {
         length = qstrlen(data);
     }
     if (length < 3 || data[0] != '0' || data[1] != 'x') { // must be at least 0xD
         if (ok) {
             *ok = false;
         }
         return QByteArray();
     }
     data += 2; // eat 0x
     length -= 2;
     QByteArray array;
     if (!hexToByteArrayInternal(data, length, &array)) {
         if (ok) {
             *ok = false;
         }
         array.clear();
     }
     if (ok) {
         *ok = true;
     }
     return array;
 }
 
 QList<int> KDb::stringListToIntList(const QStringList &list, bool *ok)
 {
     QList<int> result;
     foreach (const QString &item, list) {
         int val = item.toInt(ok);
         if (ok && !*ok) {
             return QList<int>();
         }
         result.append(val);
     }
     if (ok) {
         *ok = true;
     }
     return result;
 }
 
 // Based on KConfigGroupPrivate::serializeList() from kconfiggroup.cpp (kdelibs 4)
 QString KDb::serializeList(const QStringList &list)
 {
     QString value;
 
     if (!list.isEmpty()) {
         QStringList::ConstIterator it = list.constBegin();
         const QStringList::ConstIterator end = list.constEnd();
 
         value = QString(*it).replace(QLatin1Char('\\'), QLatin1String("\\\\"))
                             .replace(QLatin1Char(','), QLatin1String("\\,"));
 
         while (++it != end) {
             // In the loop, so it is not done when there is only one element.
             // Doing it repeatedly is a pretty cheap operation.
             value.reserve(4096);
 
             value += QLatin1Char(',')
                      + QString(*it).replace(QLatin1Char('\\'), QLatin1String("\\\\"))
                                    .replace(QLatin1Char(','), QLatin1String("\\,"));
         }
 
         // To be able to distinguish an empty list from a list with one empty element.
         if (value.isEmpty())
             value = QLatin1String("\\0");
     }
 
     return value;
 }
 
 // Based on KConfigGroupPrivate::deserializeList() from kconfiggroup.cpp (kdelibs 4)
 QStringList KDb::deserializeList(const QString &data)
 {
     if (data.isEmpty())
         return QStringList();
     if (data == QLatin1String("\\0"))
         return QStringList(QString());
     QStringList value;
     QString val;
     val.reserve(data.size());
     bool quoted = false;
     for (int p = 0; p < data.length(); p++) {
         if (quoted) {
             val += data[p];
             quoted = false;
         } else if (data[p].unicode() == QLatin1Char('\\')) {
             quoted = true;
         } else if (data[p].unicode() == QLatin1Char(',')) {
             val.squeeze(); // release any unused memory
             value.append(val);
             val.clear();
             val.reserve(data.size() - p);
         } else {
             val += data[p];
         }
     }
     value.append(val);
     return value;
 }
 
 QList<int> KDb::deserializeIntList(const QString &data, bool *ok)
 {
     return KDb::stringListToIntList(
         KDb::deserializeList(data), ok);
 }
 
 QString KDb::variantToString(const QVariant& v)
  {
     if (v.type() == QVariant::ByteArray) {
         return KDb::escapeBLOB(v.toByteArray(), KDb::BLOBEscapingType::Hex);
     }
     else if (v.type() == QVariant::StringList) {
         return serializeList(v.toStringList());
     }
     return v.toString();
 }
 
 QVariant KDb::stringToVariant(const QString& s, QVariant::Type type, bool* ok)
 {
     if (s.isNull()) {
         if (ok)
             *ok = true;
         return QVariant();
     }
     switch (type) {
     case QVariant::Invalid:
         if (ok)
             *ok = false;
         return QVariant();
     case QVariant::ByteArray: {//special case: hex string
         const int len = s.length();
         QByteArray ba;
         ba.resize(len / 2 + len % 2);
         for (int i = 0; i < (len - 1); i += 2) {
             bool _ok;
             int c = s.midRef(i, 2).toInt(&_ok, 16);
             if (!_ok) {
                 if (ok)
                     *ok = _ok;
                 kdbWarning() << "Error in digit" << i;
                 return QVariant();
             }
             ba[i/2] = (char)c;
         }
         if (ok)
             *ok = true;
         return ba;
     }
     case QVariant::StringList:
         *ok = true;
         return KDb::deserializeList(s);
     default:;
     }
 
     QVariant result(s);
     if (!result.convert(type)) {
         if (ok)
             *ok = false;
         return QVariant();
     }
     if (ok)
         *ok = true;
     return result;
 }
 
 bool KDb::isDefaultValueAllowed(const KDbField &field)
 {
     return !field.isUniqueKey();
 }
 
 void KDb::getLimitsForFieldType(KDbField::Type type, qlonglong *minValue, qlonglong *maxValue,
                                 Signedness signedness)
 {
     if (!minValue || !maxValue) {
         return;
     }
     switch (type) {
     case KDbField::Byte:
 //! @todo always ok?
         *minValue = signedness == KDb::Signed ? -0x80 : 0;
         *maxValue = signedness == KDb::Signed ? 0x7F : 0xFF;
         break;
     case KDbField::ShortInteger:
         *minValue = signedness == KDb::Signed ? -0x8000 : 0;
         *maxValue = signedness == KDb::Signed ? 0x7FFF : 0xFFFF;
         break;
     case KDbField::Integer:
     case KDbField::BigInteger: //!< @todo cannot return anything larger?
     default:
         *minValue = signedness == KDb::Signed ? qlonglong(-0x07FFFFFFF) : qlonglong(0);
         *maxValue = signedness == KDb::Signed ? qlonglong(0x07FFFFFFF) : qlonglong(0x0FFFFFFFF);
     }
 }
 
 KDbField::Type KDb::maximumForIntegerFieldTypes(KDbField::Type t1, KDbField::Type t2)
 {
     if (!KDbField::isIntegerType(t1) || !KDbField::isIntegerType(t2))
         return KDbField::InvalidType;
     if (t1 == t2)
         return t2;
     if (t1 == KDbField::ShortInteger && t2 != KDbField::Integer && t2 != KDbField::BigInteger)
         return t1;
     if (t1 == KDbField::Integer && t2 != KDbField::BigInteger)
         return t1;
     if (t1 == KDbField::BigInteger)
         return t1;
     return KDb::maximumForIntegerFieldTypes(t2, t1); //swap
 }
 
 QString KDb::simplifiedFieldTypeName(KDbField::Type type)
 {
     if (KDbField::isNumericType(type))
         return KDbField::tr("Number"); //simplify
     else if (type == KDbField::BLOB)
 //! @todo support names of other BLOB subtypes
         return KDbField::tr("Image"); //simplify
 
     return KDbField::typeGroupName(KDbField::typeGroup(type));
 }
 
 QString KDb::defaultFileBasedDriverMimeType()
 {
     return QLatin1String("application/x-kexiproject-sqlite3");
 }
 
 QString KDb::defaultFileBasedDriverId()
 {
     return QLatin1String("org.kde.kdb.sqlite");
 }
 
 // Try to convert from string to type T
 template <typename T>
 QVariant convert(T (QString::*ConvertToT)(bool*,int) const, const char *data, int size,
                  qlonglong minValue, qlonglong maxValue, bool *ok)
 {
     T v = (QString::fromLatin1(data, size).*ConvertToT)(ok, 10);
     if (*ok) {
         *ok = minValue <= v && v <= maxValue;
     }
     return KDb::iif(*ok, QVariant(v));
 }
 
 QVariant KDb::cstringToVariant(const char* data, KDbField::Type type, bool *ok, int length,
                                KDb::Signedness signedness)
 {
     bool tempOk;
     bool *thisOk = ok ? ok : &tempOk;
     if (type < KDbField::Byte || type > KDbField::LastType) {
         *thisOk = false;
         return QVariant();
     }
     if (!data) { // NULL value
         *thisOk = true;
         return QVariant();
     }
     // from most to least frequently used types:
 
     if (KDbField::isTextType(type)) {
         *thisOk = true;
         //! @todo use KDbDriverBehavior::TEXT_TYPE_MAX_LENGTH for Text type?
         return QString::fromUtf8(data, length);
     }
     if (KDbField::isIntegerType(type)) {
         qlonglong minValue, maxValue;
         const bool isUnsigned = signedness == KDb::Unsigned;
         KDb::getLimitsForFieldType(type, &minValue, &maxValue, signedness);
         switch (type) {
         case KDbField::Byte: // Byte here too, minValue/maxValue will take care of limits
         case KDbField::ShortInteger:
             return isUnsigned ?
                 convert(&QString::toUShort, data, length, minValue, maxValue, thisOk)
                 : convert(&QString::toShort, data, length, minValue, maxValue, thisOk);
         case KDbField::Integer:
             return isUnsigned ?
                 convert(&QString::toUInt, data, length, minValue, maxValue, thisOk)
                 : convert(&QString::toInt, data, length, minValue, maxValue, thisOk);
         case KDbField::BigInteger:
             return convert(&QString::toLongLong, data, length, minValue, maxValue, thisOk);
         default:
             qFatal("Unsupported integer type %d", type);
         }
     }
     if (KDbField::isFPNumericType(type)) {
         const QVariant result(QString::fromLatin1(data, length).toDouble(thisOk));
         return KDb::iif(*thisOk, result);
     }
     if (type == KDbField::BLOB) {
         *thisOk = length >= 0;
         return *thisOk ? QVariant(QByteArray(data, length)) : QVariant();
     }
     // the default
 //! @todo date/time?
     QVariant result(QString::fromUtf8(data, length));
     if (!result.convert(KDbField::variantType(type))) {
         *thisOk = false;
         return QVariant();
     }
     *thisOk = true;
     return result;
 }
 
 QStringList KDb::libraryPaths()
 {
     QStringList result;
     foreach (const QString& path, qApp->libraryPaths()) {
         const QString dir(path + QLatin1Char('/') + QLatin1String(KDB_BASE_NAME_LOWER));
         if (QDir(dir).exists() && QDir(dir).isReadable()) {
             result += dir;
         }
     }
     return result;
 }
 
 QString KDb::temporaryTableName(KDbConnection *conn, const QString &baseName)
 {
     if (!conn) {
         return QString();
     }
     while (true) {
         QString name = QLatin1String("tmp__") + baseName;
         for (int i = 0; i < 10; ++i) {
             name += QString::number(int(double(qrand()) / RAND_MAX * 0x10), 16);
         }
         const tristate res = conn->containsTable(name);
         if (~res) {
             return QString();
         } else if (res == false) {
             return name;
         }
     }
 }
 
 QString KDb::sqlite3ProgramPath()
 {
     QString path = KDbUtils::findExe(QLatin1String("sqlite3"));
     if (path.isEmpty()) {
         kdbWarning() << "Could not find program \"sqlite3\"";
     }
     return path;
 }
 
 bool KDb::importSqliteFile(const QString &inputFileName, const QString &outputFileName)
 {
     const QString sqlite_app = KDb::sqlite3ProgramPath();
     if (sqlite_app.isEmpty()) {
         return false;
     }
 
     QFileInfo fi(inputFileName);
     if (!fi.isReadable()) {
         kdbWarning() << "No readable input file" << fi.absoluteFilePath();
         return false;
     }
     QFileInfo fo(outputFileName);
     if (QFile(fo.absoluteFilePath()).exists()) {
         if (!QFile::remove(fo.absoluteFilePath())) {
             kdbWarning() << "Could not remove output file" << fo.absoluteFilePath();
             return false;
         }
     }
     kdbDebug() << inputFileName << fi.absoluteDir().path() << fo.absoluteFilePath();
 
     QProcess p;
     p.start(sqlite_app, QStringList() << fo.absoluteFilePath());
     if (!p.waitForStarted()) {
         kdbWarning() << "Failed to start program" << sqlite_app;
         return false;
     }
     QByteArray line(".read " + QFile::encodeName(fi.absoluteFilePath()));
     if (p.write(line) != line.length() || !p.waitForBytesWritten()) {
         kdbWarning() << "Failed to send \".read\" command to program" << sqlite_app;
         return false;
     }
     p.closeWriteChannel();
     if (!p.waitForFinished()) {
         kdbWarning() << "Failed to finish program" << sqlite_app;
         return false;
     }
     return true;
 }
 
 //---------
 
 bool KDb::isIdentifier(const QString& s)
 {
     int i;
     const int sLength = s.length();
     for (i = 0; i < sLength; i++) {
         const char c = s.at(i).toLower().toLatin1();
         if (c == 0 || !(c == '_' || (c >= 'a' && c <= 'z') || (i > 0 && c >= '0' && c <= '9')))
             break;
     }
     return i > 0 && i == sLength;
 }
 
 bool KDb::isIdentifier(const QByteArray& s)
 {
     int i;
     const int sLength = s.length();
     for (i = 0; i < sLength; i++) {
         const char c = s.at(i);
         if (c == 0 || !(c == '_' || (c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z') || (i > 0 && c >= '0' && c <= '9'))) {
             break;
         }
     }
     return i > 0 && i == sLength;
 }
 
 static inline QString charToIdentifier(const QChar& c)
 {
     if (c.unicode() >= TRANSLITERATION_TABLE_SIZE)
         return QLatin1String("_");
     const char *const s = transliteration_table[c.unicode()];
     return s ? QString::fromLatin1(s) : QLatin1String("_");
 }
 
 QString KDb::stringToIdentifier(const QString &s)
 {
     if (s.isEmpty())
         return QString();
     QString r, id = s.simplified();
     if (id.isEmpty())
         return QString();
     r.reserve(id.length());
     id.replace(QLatin1Char(' '), QLatin1String("_"));
     const QChar c = id[0];
     const char ch = c.toLatin1();
     QString add;
     bool wasUnderscore = false;
 
     if (ch >= '0' && ch <= '9') {
         r += QLatin1Char('_') + c;
     } else {
         add = charToIdentifier(c);
         r += add;
         wasUnderscore = add == QLatin1String("_");
     }
 
     const int idLength = id.length();
     for (int i = 1; i < idLength; i++) {
         add = charToIdentifier(id.at(i));
         if (wasUnderscore && add == QLatin1String("_"))
             continue;
         wasUnderscore = add == QLatin1String("_");
         r += add;
     }
     return r;
 }
 
 QString KDb::identifierExpectedMessage(const QString &valueName, const QVariant& v)
 {
     return QLatin1String("<p>") + kdb::tr("Value of \"%1\" field must be an identifier.")
             .arg(valueName)
            + QLatin1String("</p><p>")
            + kdb::tr("\"%1\" is not a valid identifier.").arg(v.toString()) + QLatin1String("</p>");
 }
 
 //--------------------------------------------------------------------------------
 
 #ifdef KDB_DEBUG_GUI
 
-static KDb::DebugGUIHandler s_debugGUIHandler = 0;
+static KDb::DebugGUIHandler s_debugGUIHandler = nullptr;
 
 void KDb::setDebugGUIHandler(KDb::DebugGUIHandler handler)
 {
     s_debugGUIHandler = handler;
 }
 
 void KDb::debugGUI(const QString& text)
 {
     if (s_debugGUIHandler)
         s_debugGUIHandler(text);
 }
 
-static KDb::AlterTableActionDebugGUIHandler s_alterTableActionDebugHandler = 0;
+static KDb::AlterTableActionDebugGUIHandler s_alterTableActionDebugHandler = nullptr;
 
 void KDb::setAlterTableActionDebugHandler(KDb::AlterTableActionDebugGUIHandler handler)
 {
     s_alterTableActionDebugHandler = handler;
 }
 
 void KDb::alterTableActionDebugGUI(const QString& text, int nestingLevel)
 {
     if (s_alterTableActionDebugHandler)
         s_alterTableActionDebugHandler(text, nestingLevel);
 }
 
 #endif // KDB_DEBUG_GUI
 
 #include "KDb.moc"