diff --git a/src/AddRecordDialog.cpp b/src/AddRecordDialog.cpp
index 406e745d..5a6a5f19 100644
--- a/src/AddRecordDialog.cpp
+++ b/src/AddRecordDialog.cpp
@@ -17,7 +17,7 @@ private:
     bool m_isNull;
 
 public:
-    NullLineEdit(QWidget* parent=nullptr): QLineEdit(parent), m_isNull (true) {}
+    explicit NullLineEdit(QWidget* parent=nullptr): QLineEdit(parent), m_isNull (true) {}
 
     bool isNull() {return m_isNull;}
     void setNull(bool value) {
@@ -65,7 +65,7 @@ protected:
 // Styled Item Delegate for non-editable columns (all except Value)
 class NoEditDelegate: public QStyledItemDelegate {
 public:
-    NoEditDelegate(QObject* parent=nullptr): QStyledItemDelegate(parent) {}
+    explicit NoEditDelegate(QObject* parent=nullptr): QStyledItemDelegate(parent) {}
     QWidget* createEditor(QWidget* /* parent */, const QStyleOptionViewItem& /* option */, const QModelIndex& /* index */) const override {
         return nullptr;
     }
@@ -75,7 +75,7 @@ public:
 class EditDelegate: public QStyledItemDelegate {
 
 public:
-    EditDelegate(QObject* parent=nullptr): QStyledItemDelegate(parent) {}
+    explicit EditDelegate(QObject* parent=nullptr): QStyledItemDelegate(parent) {}
     QWidget* createEditor(QWidget *parent, const QStyleOptionViewItem& /* option */, const QModelIndex& /* index */) const override {
         return new NullLineEdit(parent);
     }
@@ -180,7 +180,7 @@ void AddRecordDialog::populateFields()
     ui->treeWidget->setItemDelegateForColumn(kValue, new EditDelegate(this));
 
     sqlb::FieldVector fields;
-    QVector<sqlb::ConstraintPtr> fks;
+    std::vector<sqlb::ConstraintPtr> fks;
     QStringList pk;
 
     // Initialize fields, fks and pk differently depending on whether it's a table or a view.
@@ -190,12 +190,12 @@ void AddRecordDialog::populateFields()
         sqlb::TablePtr m_table = pdb.getObjectByName<sqlb::Table>(curTable);
         fields = m_table->fields;
         for(const sqlb::Field& f : fields)
-            fks.append(m_table->constraint({f.name()}, sqlb::Constraint::ForeignKeyConstraintType));
+            fks.push_back(m_table->constraint({f.name()}, sqlb::Constraint::ForeignKeyConstraintType));
         pk = m_table->primaryKey();
     } else {
         sqlb::ViewPtr m_view = pdb.getObjectByName<sqlb::View>(curTable);
         fields = m_view->fields;
-        fks.fill(sqlb::ConstraintPtr(nullptr), fields.size());
+        fks.resize(fields.size(), sqlb::ConstraintPtr(nullptr));
         for(const auto& col : pseudo_pk)
             pk << QString::fromStdString(col);
     }
diff --git a/src/CipherSettings.cpp b/src/CipherSettings.cpp
index 3fe58b95..fa1acfeb 100644
--- a/src/CipherSettings.cpp
+++ b/src/CipherSettings.cpp
@@ -1,5 +1,12 @@
 #include "CipherSettings.h"
 
+CipherSettings::CipherSettings()
+    : keyFormat(Passphrase),
+      pageSize(0),
+      kdfIterations(0)
+{
+}
+
 CipherSettings::KeyFormats CipherSettings::getKeyFormat() const
 {
     return keyFormat;
diff --git a/src/CipherSettings.h b/src/CipherSettings.h
index 7fe992fd..139b043a 100644
--- a/src/CipherSettings.h
+++ b/src/CipherSettings.h
@@ -6,6 +6,8 @@
 class CipherSettings
 {
 public:
+    CipherSettings();
+
     enum KeyFormats
     {
         Passphrase,
diff --git a/src/CondFormat.cpp b/src/CondFormat.cpp
index 9d87c3ca..3b76bf80 100644
--- a/src/CondFormat.cpp
+++ b/src/CondFormat.cpp
@@ -4,8 +4,8 @@
 
 CondFormat::CondFormat(const QString& filter, const QColor& foreground, const QColor& background, const QString& encoding)
     : m_filter(filter),
-      m_fgColor(foreground),
-      m_bgColor(background)
+      m_bgColor(background),
+      m_fgColor(foreground)
 {
     if (!filter.isEmpty())
         m_sqlCondition = filterToSqlCondition(filter, encoding);
diff --git a/src/CondFormat.h b/src/CondFormat.h
index 9e1d69b4..20a81346 100644
--- a/src/CondFormat.h
+++ b/src/CondFormat.h
@@ -8,7 +8,7 @@
 class CondFormat
 {
 public:
-    CondFormat() {};
+    CondFormat() {}
     explicit CondFormat(const QString& filter, const QColor& foreground, const QColor& background, const QString& encoding = QString());
 
     static QString filterToSqlCondition(const QString& value, const QString& encoding = QString());
@@ -20,10 +20,10 @@ private:
     QColor m_fgColor;
 
 public:
-    QString sqlCondition() const { return m_sqlCondition; };
-    QString filter() const { return m_filter; };
-    QColor backgroundColor() const { return m_bgColor; };
-    QColor foregroundColor() const { return m_fgColor; };
+    QString sqlCondition() const { return m_sqlCondition; }
+    QString filter() const { return m_filter; }
+    QColor backgroundColor() const { return m_bgColor; }
+    QColor foregroundColor() const { return m_fgColor; }
 
 };
 
diff --git a/src/Data.cpp b/src/Data.cpp
index f123cdda..e34152e4 100644
--- a/src/Data.cpp
+++ b/src/Data.cpp
@@ -73,7 +73,7 @@ QByteArray removeBom(QByteArray& data)
     }
 }
 
-QStringList toStringList(const QList<QByteArray> list) {
+QStringList toStringList(const QList<QByteArray>& list) {
     QStringList strings;
     for (const QByteArray &item : list) {
         strings.append(QString::fromUtf8(item));
diff --git a/src/Data.h b/src/Data.h
index c9881e7c..df6a708f 100644
--- a/src/Data.h
+++ b/src/Data.h
@@ -18,7 +18,7 @@ bool startsWithBom(const QByteArray& data);
 // with a BOM an empty byte array is returned and the original data is not modified.
 QByteArray removeBom(QByteArray& data);
 
-QStringList toStringList(const QList<QByteArray> list);
+QStringList toStringList(const QList<QByteArray>& list);
 
 QByteArray encodeString(const QByteArray& str, const QString& encoding);
 
diff --git a/src/EditIndexDialog.cpp b/src/EditIndexDialog.cpp
index d24aa464..dca0a2cd 100644
--- a/src/EditIndexDialog.cpp
+++ b/src/EditIndexDialog.cpp
@@ -117,7 +117,7 @@ void EditIndexDialog::updateColumnLists()
     if(!table)
         return;
     sqlb::FieldInfoList tableFields = table->fieldInformation();
-    ui->tableTableColumns->setRowCount(tableFields.size());
+    ui->tableTableColumns->setRowCount(static_cast<int>(tableFields.size()));
     int tableRows = 0;
     for(size_t i=0;i<tableFields.size();++i)
     {
@@ -147,7 +147,7 @@ void EditIndexDialog::updateColumnLists()
     // table) and to preserve the order of the index columns
     auto indexFields = index.fields;
     ui->tableIndexColumns->blockSignals(true);
-    ui->tableIndexColumns->setRowCount(indexFields.size());
+    ui->tableIndexColumns->setRowCount(static_cast<int>(indexFields.size()));
     for(size_t i=0;i<indexFields.size();++i)
     {
         // Put the name of the field in the first column
diff --git a/src/EditTableDialog.cpp b/src/EditTableDialog.cpp
index 4193f1e8..2478f798 100644
--- a/src/EditTableDialog.cpp
+++ b/src/EditTableDialog.cpp
@@ -168,7 +168,7 @@ void EditTableDialog::populateConstraints()
     const auto& constraints = m_table.allConstraints();
 
     ui->tableConstraints->blockSignals(true);
-    ui->tableConstraints->setRowCount(constraints.size());
+    ui->tableConstraints->setRowCount(static_cast<int>(constraints.size()));
     int row = 0;
     for(const auto& pair : constraints)
     {
@@ -609,7 +609,7 @@ void EditTableDialog::addField()
     // Find an unused name for the field by starting with 'Fieldx' where x is the number of fields + 1.
     // If this name happens to exist already, increase x by one until we find an unused name.
     {
-        unsigned int field_number = ui->treeWidget->topLevelItemCount();
+        int field_number = ui->treeWidget->topLevelItemCount();
         QString field_name;
         do
         {
diff --git a/src/ExportDataDialog.cpp b/src/ExportDataDialog.cpp
index ead29b0f..bc08ede2 100644
--- a/src/ExportDataDialog.cpp
+++ b/src/ExportDataDialog.cpp
@@ -91,9 +91,9 @@ bool ExportDataDialog::exportQuery(const QString& sQuery, const QString& sFilena
         return exportQueryCsv(sQuery, sFilename);
     case ExportFormatJson:
         return exportQueryJson(sQuery, sFilename);
-    default:
-        return false;
     }
+
+    return false;
 }
 
 bool ExportDataDialog::exportQueryCsv(const QString& sQuery, const QString& sFilename)
diff --git a/src/FileDialog.h b/src/FileDialog.h
index 8310bc31..c2877824 100644
--- a/src/FileDialog.h
+++ b/src/FileDialog.h
@@ -31,15 +31,15 @@ class FileDialog : public QFileDialog
 public:
     static QString getOpenFileName(const FileDialogTypes dialogType, QWidget* parent = nullptr, const QString& caption = QString(),
                                    const QString& filter = QString(), QString* selectedFilter = nullptr,
-                                   Options options = 0);
+                                   Options options = Options());
     static QStringList getOpenFileNames(const FileDialogTypes dialogType, QWidget* parent = nullptr, const QString& caption = QString(),
                                         const QString& filter = QString(), QString* selectedFilter = nullptr,
-                                        Options options = 0);
+                                        Options options = Options());
     static QString getSaveFileName(const FileDialogTypes dialogType, QWidget* parent = nullptr, const QString& caption = QString(),
                                    const QString& filter = QString(), const QString& defaultFileName = QString(), QString* selectedFilter = nullptr,
-                                   Options options = 0);
+                                   Options options = Options());
     static QString getExistingDirectory(const FileDialogTypes dialogType, QWidget* parent = nullptr, const QString& caption = QString(),
-                                        Options options = 0);
+                                        Options options = Options());
 
     static QString getSqlDatabaseFileFilter();
 
diff --git a/src/ForeignKeyEditorDelegate.cpp b/src/ForeignKeyEditorDelegate.cpp
index 0b8c3520..d226d73d 100644
--- a/src/ForeignKeyEditorDelegate.cpp
+++ b/src/ForeignKeyEditorDelegate.cpp
@@ -122,7 +122,7 @@ void ForeignKeyEditorDelegate::setEditorData(QWidget* editor, const QModelIndex&
 {
     ForeignKeyEditor* fkEditor = static_cast<ForeignKeyEditor*>(editor);
 
-    int column = index.row(); // weird? I know right
+    size_t column = static_cast<size_t>(index.row()); // weird? I know right
     const sqlb::Field& field = m_table.fields.at(column);
     auto fk = std::dynamic_pointer_cast<sqlb::ForeignKeyClause>(m_table.constraint({field.name()}, sqlb::Constraint::ForeignKeyConstraintType));
     if (fk) {
@@ -140,7 +140,7 @@ void ForeignKeyEditorDelegate::setModelData(QWidget* editor, QAbstractItemModel*
     ForeignKeyEditor* fkEditor = static_cast<ForeignKeyEditor*>(editor);
     QString sql = fkEditor->getSql();
 
-    int column = index.row();
+    size_t column = static_cast<size_t>(index.row());
     const sqlb::Field& field = m_table.fields.at(column);
     if (sql.isEmpty()) {
         // Remove the foreign key
diff --git a/src/ImportCsvDialog.cpp b/src/ImportCsvDialog.cpp
index e61f7115..4262d68d 100644
--- a/src/ImportCsvDialog.cpp
+++ b/src/ImportCsvDialog.cpp
@@ -43,7 +43,7 @@ ImportCsvDialog::ImportCsvDialog(const QStringList &filenames, DBBrowserDB* db,
 
     // Create a list of all available encodings and create an auto completion list from them
     QStringList encodingList;
-    for(const QString& enc : QTextCodec::availableCodecs())
+    for(const QByteArray& enc : QTextCodec::availableCodecs())
         encodingList.push_back(enc);
     encodingCompleter = new QCompleter(encodingList, this);
     encodingCompleter->setCaseSensitivity(Qt::CaseInsensitive);
@@ -136,17 +136,17 @@ public:
         m_pProgressDlg->setWindowModality(Qt::ApplicationModal);
     }
 
-    ~CSVImportProgress()
+    ~CSVImportProgress() override
     {
         delete m_pProgressDlg;
     }
 
-    void start()
+    void start() override
     {
         m_pProgressDlg->show();
     }
 
-    bool update(unsigned long long pos)
+    bool update(unsigned long long pos) override
     {
         m_pProgressDlg->setValue(static_cast<int>((static_cast<float>(pos) / static_cast<float>(totalFileSize)) * 10000.0f));
         qApp->processEvents();
@@ -154,7 +154,7 @@ public:
         return !m_pProgressDlg->wasCanceled();
     }
 
-    void end()
+    void end() override
     {
         m_pProgressDlg->hide();
     }
@@ -236,7 +236,7 @@ void ImportCsvDialog::updatePreview()
 
     // Reset preview widget
     ui->tablePreview->clear();
-    ui->tablePreview->setColumnCount(fieldList.size());
+    ui->tablePreview->setColumnCount(static_cast<int>(fieldList.size()));
 
     // Exit if there are no lines to preview at all
     if(fieldList.size() == 0)
diff --git a/src/MainWindow.cpp b/src/MainWindow.cpp
index ea8bb9af..9765f450 100644
--- a/src/MainWindow.cpp
+++ b/src/MainWindow.cpp
@@ -103,8 +103,8 @@ MainWindow::MainWindow(QWidget* parent)
       remoteDock(new RemoteDock(this)),
       findReplaceDialog(new FindReplaceDialog(this)),
       gotoValidator(new QIntValidator(0, 0, this)),
-      isProjectModified(false),
-      execute_sql_worker(nullptr)
+      execute_sql_worker(nullptr),
+      isProjectModified(false)
 {
     ui->setupUi(this);
     init();
@@ -1504,10 +1504,10 @@ void MainWindow::executeQuery()
         // Log the query and the result message.
         // The query takes the last placeholder as it may itself contain the sequence '%' + number.
         QString query = editor->text(from_position, to_position);
-        QString log_message = QString("-- " + tr("At line %1:") + "\n%3\n-- " + tr("Result: %2")).arg(execute_from_line+1).arg(status_message).arg(query.trimmed());
+        QString log_message = "-- " + tr("At line %1:").arg(execute_from_line+1) + "\n" + query.trimmed() + "\n-- " + tr("Result: %1").arg(status_message);
         db.logSQL(log_message, kLogMsg_User);
 
-        log_message = QString(tr("Result: %2") + "\n" + tr("At line %1:") + "\n%3").arg(execute_from_line+1).arg(status_message).arg(query.trimmed());
+        log_message = tr("Result: %2").arg(status_message) + "\n" + tr("At line %1:").arg(execute_from_line+1) + "\n" + query.trimmed();
         // Update the execution area
         sqlWidget->finishExecution(log_message, ok);
     };
@@ -2918,7 +2918,7 @@ bool MainWindow::loadProject(QString filename, bool readOnly)
                         if(xml.name() == "sql")
                         {
                             // SQL editor tab
-                            unsigned int index = openSqlTab();
+                            int index = openSqlTab();
                             ui->tabSqlAreas->setTabText(index, xml.attributes().value("name").toString());
                             SqlTextEdit* sqlEditor = qobject_cast<SqlExecutionArea*>(ui->tabSqlAreas->widget(index))->getEditor();
                             sqlEditor->setText(xml.readElementText());
@@ -3456,9 +3456,9 @@ void MainWindow::editDataColumnDisplayFormat()
     int field_number = sender()->property("clicked_column").toInt();
     QString field_name;
     if (db.getObjectByName(current_table)->type() == sqlb::Object::Table)
-      field_name = db.getObjectByName<sqlb::Table>(current_table)->fields.at(field_number-1).name();
+        field_name = db.getObjectByName<sqlb::Table>(current_table)->fields.at(field_number-1).name();
     else
-      field_name = db.getObjectByName<sqlb::View>(current_table)->fieldNames().at(field_number-1);
+        field_name = db.getObjectByName<sqlb::View>(current_table)->fieldNames().at(field_number-1);
     // Get the current display format of the field
     QString current_displayformat = browseTableSettings[current_table].displayFormats[field_number];
 
@@ -3862,7 +3862,7 @@ void MainWindow::runSqlNewTab(const QString& query, const QString& title)
         if (ui->mainTab->indexOf(ui->query) == -1)
             ui->mainTab->addTab(ui->query, ui->query->accessibleName());
         ui->mainTab->setCurrentWidget(ui->query);
-        unsigned int index = openSqlTab();
+        int index = openSqlTab();
         ui->tabSqlAreas->setTabText(index, title);
         qobject_cast<SqlExecutionArea*>(ui->tabSqlAreas->widget(index))->getEditor()->setText(query);
         executeQuery();
diff --git a/src/PlotDock.cpp b/src/PlotDock.cpp
index 256a9dc2..7878436e 100644
--- a/src/PlotDock.cpp
+++ b/src/PlotDock.cpp
@@ -7,6 +7,7 @@
 
 #include <QPrinter>
 #include <QPrintPreviewDialog>
+#include <QRandomGenerator>
 
 PlotDock::PlotDock(QWidget* parent)
     : QDialog(parent),
@@ -524,7 +525,7 @@ void PlotDock::on_treePlotColumns_itemDoubleClicked(QTreeWidgetItem* item, int c
         // On double click open the colordialog
         QColorDialog colordialog(this);
         QColor curbkcolor = item->backgroundColor(column);
-        QColor precolor = !curbkcolor.isValid() ? static_cast<Qt::GlobalColor>(qrand() % 13 + 5) : curbkcolor;
+        QColor precolor = !curbkcolor.isValid() ? static_cast<Qt::GlobalColor>(QRandomGenerator::global()->bounded(5, 13)) : curbkcolor;
         QColor color = colordialog.getColor(precolor, this, tr("Choose an axis color"));
         if(color.isValid())
         {
diff --git a/src/RowLoader.cpp b/src/RowLoader.cpp
index 3046567e..1b12cc03 100644
--- a/src/RowLoader.cpp
+++ b/src/RowLoader.cpp
@@ -35,7 +35,7 @@ RowLoader::RowLoader (
 {
 }
 
-void RowLoader::setQuery (QString new_query, QString newCountQuery)
+void RowLoader::setQuery (const QString& new_query, const QString& newCountQuery)
 {
     std::lock_guard<std::mutex> lk(m);
     query = new_query;
diff --git a/src/RowLoader.h b/src/RowLoader.h
index 5fb11808..3a7ae295 100644
--- a/src/RowLoader.h
+++ b/src/RowLoader.h
@@ -34,7 +34,7 @@ public:
         Cache & cache_data
         );
 
-    void setQuery (QString new_query, QString newCountQuery = QString());
+    void setQuery (const QString& new_query, const QString& newCountQuery = QString());
 
     void triggerRowCountDetermination (int token);
 
diff --git a/src/RunSql.cpp b/src/RunSql.cpp
index b090a397..1b848a37 100644
--- a/src/RunSql.cpp
+++ b/src/RunSql.cpp
@@ -147,7 +147,7 @@ bool RunSql::executeNextStatement()
     acquireDbAccess();
     sqlite3_stmt* vm;
     int sql3status = sqlite3_prepare_v2(pDb.get(), tail, tail_length, &vm, &tail);
-    QString queryPart = QString::fromUtf8(qbegin, tail - qbegin);
+    QString queryPart = QString::fromUtf8(qbegin, static_cast<int>(tail - qbegin));
     int tail_length_before = tail_length;
     tail_length -= (tail - qbegin);
     int end_of_current_statement_position = execute_current_position + tail_length_before - tail_length;
diff --git a/src/Settings.cpp b/src/Settings.cpp
index b881b1cb..087543c6 100644
--- a/src/Settings.cpp
+++ b/src/Settings.cpp
@@ -364,6 +364,7 @@ QColor Settings::getDefaultColorValue(const QString& group, const QString& name,
                 return QColor(Qt::lightGray).name();
             if(name == "bin_bg_colour")
                 return QPalette().color(QPalette::Active, QPalette::Base).name();
+            break;
         case DarkStyle :
             if(name == "null_fg_colour")
                 return QColor("#787878");
@@ -377,6 +378,7 @@ QColor Settings::getDefaultColorValue(const QString& group, const QString& name,
                 return QColor("#787878");
             if(name == "bin_bg_colour")
                 return QColor("#19232D");
+            break;
         }
     }
 
diff --git a/src/sql/Query.cpp b/src/sql/Query.cpp
index 4472ae21..73fbed3a 100644
--- a/src/sql/Query.cpp
+++ b/src/sql/Query.cpp
@@ -5,10 +5,6 @@
 namespace sqlb
 {
 
-Query::Query()
-{
-}
-
 void Query::clear()
 {
     m_table.clear();
@@ -81,7 +77,7 @@ std::string Query::buildQuery(bool withRowid) const
     std::string order_by;
     for(const auto& sorted_column : m_sort)
     {
-        if(sorted_column.column < static_cast<int>(m_column_names.size()))
+        if(sorted_column.column < m_column_names.size())
             order_by += sqlb::escapeIdentifier(m_column_names.at(sorted_column.column)) + " "
                     + (sorted_column.direction == sqlb::Ascending ? "ASC" : "DESC") + ",";
     }
diff --git a/src/sql/Query.h b/src/sql/Query.h
index 2e7fdc94..b166b921 100644
--- a/src/sql/Query.h
+++ b/src/sql/Query.h
@@ -18,7 +18,7 @@ enum SortDirection
 
 struct SortedColumn
 {
-    SortedColumn(int column_, SortDirection direction_) :
+    SortedColumn(size_t column_, SortDirection direction_) :
         column(column_),
         direction(direction_)
     {}
@@ -28,7 +28,7 @@ struct SortedColumn
         return column == rhs.column && direction == rhs.direction;
     }
 
-    int column;
+    size_t column;
     SortDirection direction;
 };
 
@@ -46,8 +46,8 @@ struct SelectedColumn
 class Query
 {
 public:
-    Query();
-    Query(const sqlb::ObjectIdentifier& table) :
+    Query() {}
+    explicit Query(const sqlb::ObjectIdentifier& table) :
         m_table(table)
     {}
 
@@ -69,8 +69,8 @@ public:
     const std::vector<SelectedColumn>& selectedColumns() const { return m_selected_columns; }
     std::vector<SelectedColumn>& selectedColumns() { return m_selected_columns; }
 
-    const std::unordered_map<int, std::string>& where() const { return m_where; }
-    std::unordered_map<int, std::string>& where() { return m_where; }
+    const std::unordered_map<size_t, std::string>& where() const { return m_where; }
+    std::unordered_map<size_t, std::string>& where() { return m_where; }
 
     const std::vector<SortedColumn>& orderBy() const { return m_sort; }
     std::vector<SortedColumn>& orderBy() { return m_sort; }
@@ -81,7 +81,7 @@ private:
     sqlb::ObjectIdentifier m_table;
     std::vector<std::string> m_rowid_columns;
     std::vector<SelectedColumn> m_selected_columns;
-    std::unordered_map<int, std::string> m_where;
+    std::unordered_map<size_t, std::string> m_where;
     std::vector<SortedColumn> m_sort;
 
     std::vector<SelectedColumn>::iterator findSelectedColumnByName(const std::string& name);
diff --git a/src/sql/sqlitetypes.cpp b/src/sql/sqlitetypes.cpp
index d1028a89..560713ab 100644
--- a/src/sql/sqlitetypes.cpp
+++ b/src/sql/sqlitetypes.cpp
@@ -39,12 +39,12 @@ std::string escapeIdentifier(std::string id)
     return escapeIdentifier(QString::fromStdString(id)).toStdString();
 }
 
-QStringList escapeIdentifier(const QStringList& ids)
+QStringList escapeIdentifier(QStringList ids)
 {
-    QStringList ret;
-    for(const QString& id : ids)
-        ret.push_back(escapeIdentifier(id));
-    return ret;
+    std::transform(ids.begin(), ids.end(), ids.begin(), [](const QString& id) {
+        return escapeIdentifier(id);
+    });
+    return ids;
 }
 
 /**
@@ -59,10 +59,8 @@ class SetLocaleToC
 {
 public:
     SetLocaleToC()
+        : oldLocale(std::setlocale(LC_CTYPE, nullptr))      // Query current locale and save it
     {
-        // Query current locale and save it
-        oldLocale = std::setlocale(LC_CTYPE, nullptr);
-
         // Set locale for standard library functions
         std::setlocale(LC_CTYPE, "C.UTF-8");
     }
@@ -342,8 +340,7 @@ Table& Table::operator=(const Table& rhs)
 
     // Make copies of the fields and the constraints. This is necessary in order to avoid any unwanted changes to the application's main database
     // schema representation just by modifying a reference to the fields or constraints and thinking it operates on a copy.
-    for(const Field& f : rhs.fields)
-        fields.push_back(f);
+    std::copy(rhs.fields.begin(), rhs.fields.end(), std::back_inserter(fields));
     m_constraints = rhs.m_constraints;
 
     return *this;
@@ -428,11 +425,7 @@ FieldInfoList Table::fieldInformation() const
 
 bool Table::hasAutoIncrement() const
 {
-    for(const Field& f : fields) {
-        if(f.autoIncrement())
-            return true;
-    }
-    return false;
+    return std::any_of(fields.begin(), fields.end(), [](const Field& f) {return f.autoIncrement(); });
 }
 
 TablePtr Table::parseSQL(const QString& sSQL)
@@ -510,12 +503,12 @@ QString Table::sql(const QString& schema, bool ifNotExists) const
     return sql + ";";
 }
 
-void Table::addConstraint(QStringList fields, ConstraintPtr constraint)
+void Table::addConstraint(const QStringList& fields, ConstraintPtr constraint)
 {
     m_constraints.insert({fields, constraint});
 }
 
-void Table::setConstraint(QStringList fields, ConstraintPtr constraint)
+void Table::setConstraint(const QStringList& fields, ConstraintPtr constraint)
 {
     // Delete any old constraints of this type for these fields
     removeConstraints(fields, constraint->type());
@@ -524,7 +517,7 @@ void Table::setConstraint(QStringList fields, ConstraintPtr constraint)
     addConstraint(fields, constraint);
 }
 
-void Table::removeConstraints(QStringList fields, Constraint::ConstraintTypes type)
+void Table::removeConstraints(const QStringList& fields, Constraint::ConstraintTypes type)
 {
     for(auto it = m_constraints.begin();it!=m_constraints.end();)
     {
@@ -535,7 +528,7 @@ void Table::removeConstraints(QStringList fields, Constraint::ConstraintTypes ty
     }
 }
 
-ConstraintPtr Table::constraint(QStringList fields, Constraint::ConstraintTypes type) const
+ConstraintPtr Table::constraint(const QStringList& fields, Constraint::ConstraintTypes type) const
 {
     auto list = constraints(fields, type);
     if(list.size())
@@ -544,7 +537,7 @@ ConstraintPtr Table::constraint(QStringList fields, Constraint::ConstraintTypes
         return ConstraintPtr(nullptr);
 }
 
-std::vector<ConstraintPtr> Table::constraints(QStringList fields, Constraint::ConstraintTypes type) const
+std::vector<ConstraintPtr> Table::constraints(const QStringList& fields, Constraint::ConstraintTypes type) const
 {
     ConstraintMap::const_iterator begin, end;
     if(fields.empty())
@@ -1251,8 +1244,7 @@ Index& Index::operator=(const Index& rhs)
     m_whereExpr = rhs.m_whereExpr;
 
     // Make copies of the column
-    for(const IndexedColumn& c : rhs.fields)
-        fields.push_back(c);
+    std::copy(rhs.fields.begin(), rhs.fields.end(), std::back_inserter(fields));
 
     return *this;
 }
diff --git a/src/sql/sqlitetypes.h b/src/sql/sqlitetypes.h
index 16c688ea..0ccd9809 100644
--- a/src/sql/sqlitetypes.h
+++ b/src/sql/sqlitetypes.h
@@ -54,7 +54,7 @@ void setIdentifierQuoting(escapeQuoting toQuoting);
 
 QString escapeIdentifier(QString id);
 std::string escapeIdentifier(std::string id);
-QStringList escapeIdentifier(const QStringList& ids);
+QStringList escapeIdentifier(QStringList ids);
 
 class ObjectIdentifier
 {
@@ -430,11 +430,11 @@ public:
 
     FieldInfoList fieldInformation() const override;
 
-    void addConstraint(QStringList fields, ConstraintPtr constraint);
-    void setConstraint(QStringList fields, ConstraintPtr constraint);
-    void removeConstraints(QStringList fields = QStringList(), Constraint::ConstraintTypes type = Constraint::NoType); //! Only removes the first constraint, if any
-    ConstraintPtr constraint(QStringList fields = QStringList(), Constraint::ConstraintTypes type = Constraint::NoType) const;   //! Only returns the first constraint, if any
-    std::vector<ConstraintPtr> constraints(QStringList fields = QStringList(), Constraint::ConstraintTypes type = Constraint::NoType) const;
+    void addConstraint(const QStringList& fields, ConstraintPtr constraint);
+    void setConstraint(const QStringList& fields, ConstraintPtr constraint);
+    void removeConstraints(const QStringList& fields = QStringList(), Constraint::ConstraintTypes type = Constraint::NoType); //! Only removes the first constraint, if any
+    ConstraintPtr constraint(const QStringList& fields = QStringList(), Constraint::ConstraintTypes type = Constraint::NoType) const;   //! Only returns the first constraint, if any
+    std::vector<ConstraintPtr> constraints(const QStringList& fields = QStringList(), Constraint::ConstraintTypes type = Constraint::NoType) const;
     ConstraintMap allConstraints() const { return m_constraints; }
     void setConstraints(const ConstraintMap& constraints);
     QStringList& primaryKeyRef();
diff --git a/src/sqlitedb.cpp b/src/sqlitedb.cpp
index a1e1179d..a8a3a4e3 100644
--- a/src/sqlitedb.cpp
+++ b/src/sqlitedb.cpp
@@ -43,7 +43,7 @@ std::function<Ret(Params...)> Callback<Ret(Params...)>::func;
 int collCompare(void* /*pArg*/, int sizeA, const void* sA, int sizeB, const void* sB)
 {
     if(sizeA == sizeB)
-        return memcmp(sA, sB, sizeA);
+        return memcmp(sA, sB, static_cast<size_t>(sizeA));
     return sizeA - sizeB;
 }
 
@@ -687,7 +687,7 @@ bool DBBrowserDB::close()
     return true;
 }
 
-DBBrowserDB::db_pointer_type DBBrowserDB::get(QString user, bool force_wait)
+DBBrowserDB::db_pointer_type DBBrowserDB::get(const QString& user, bool force_wait)
 {
     if(!_db)
         return nullptr;
@@ -753,7 +753,7 @@ bool DBBrowserDB::dump(const QString& filePath,
         QApplication::setOverrideCursor(Qt::WaitCursor);
 
         // Count the total number of all records in all tables for the progress dialog
-        size_t numRecordsTotal = 0, numRecordsCurrent = 0;
+        size_t numRecordsTotal = 0;
         objectMap objMap = schemata["main"];            // We only always export the main database, not the attached databases
         QList<sqlb::ObjectPtr> tables = objMap.values("table");
         for(QMutableListIterator<sqlb::ObjectPtr> it(tables);it.hasNext();)
@@ -772,7 +772,7 @@ bool DBBrowserDB::dump(const QString& filePath,
         }
 
         QProgressDialog progress(tr("Exporting database to SQL file..."),
-                                 tr("Cancel"), 0, numRecordsTotal);
+                                 tr("Cancel"), 0, static_cast<int>(numRecordsTotal));
         progress.setWindowModality(Qt::ApplicationModal);
         progress.show();
         qApp->processEvents();
@@ -818,6 +818,7 @@ bool DBBrowserDB::dump(const QString& filePath,
                 {
                     int columns = sqlite3_column_count(stmt);
                     size_t counter = 0;
+                    size_t numRecordsCurrent = 0;
                     qApp->processEvents();
                     while(sqlite3_step(stmt) == SQLITE_ROW)
                     {
@@ -872,7 +873,7 @@ bool DBBrowserDB::dump(const QString& filePath,
                                 stream << ',';
                         }
 
-                        progress.setValue(++numRecordsCurrent);
+                        progress.setValue(static_cast<int>(++numRecordsCurrent));
                         if(counter % 5000 == 0)
                             qApp->processEvents();
                         counter++;
@@ -1080,7 +1081,7 @@ bool DBBrowserDB::executeMultiSQL(QByteArray query, bool dirty, bool log)
         }
 
         // Execute next statement
-        res = sqlite3_prepare_v2(_db, tail, tail_end - tail + 1, &vm, &tail);
+        res = sqlite3_prepare_v2(_db, tail, static_cast<int>(tail_end - tail + 1), &vm, &tail);
         if(res == SQLITE_OK)
         {
             switch(sqlite3_step(vm))
diff --git a/src/sqlitedb.h b/src/sqlitedb.h
index 418400c6..902efee5 100644
--- a/src/sqlitedb.h
+++ b/src/sqlitedb.h
@@ -38,7 +38,7 @@ private:
     /// custom unique_ptr deleter releases database for further use by others
     struct DatabaseReleaser
     {
-        DatabaseReleaser(DBBrowserDB * pParent_ = nullptr) : pParent(pParent_) {}
+        explicit DatabaseReleaser(DBBrowserDB * pParent_ = nullptr) : pParent(pParent_) {}
 
         DBBrowserDB * pParent;
 
@@ -91,7 +91,7 @@ public:
        \returns a unique_ptr containing the SQLite database handle, or
        nullptr in case no database is open.
     **/
-    db_pointer_type get (QString user, bool force_wait = false);
+    db_pointer_type get (const QString& user, bool force_wait = false);
 
     bool setSavepoint(const QString& pointname = "RESTOREPOINT");
     bool releaseSavepoint(const QString& pointname = "RESTOREPOINT");
diff --git a/src/sqlitetablemodel.cpp b/src/sqlitetablemodel.cpp
index 7811b478..0b83f6e8 100644
--- a/src/sqlitetablemodel.cpp
+++ b/src/sqlitetablemodel.cpp
@@ -207,7 +207,7 @@ void SqliteTableModel::setQuery(const QString& sQuery, const QString& sCountQuer
 
 int SqliteTableModel::rowCount(const QModelIndex&) const
 {
-    return m_currentRowCount;
+    return static_cast<int>(m_currentRowCount);
 }
 
 int SqliteTableModel::columnCount(const QModelIndex&) const
@@ -215,7 +215,7 @@ int SqliteTableModel::columnCount(const QModelIndex&) const
     return m_headers.size();
 }
 
-int SqliteTableModel::filterCount() const
+size_t SqliteTableModel::filterCount() const
 {
     return m_query.where().size();
 }
diff --git a/src/sqlitetablemodel.h b/src/sqlitetablemodel.h
index 8cdadf33..e891e0ff 100644
--- a/src/sqlitetablemodel.h
+++ b/src/sqlitetablemodel.h
@@ -34,7 +34,7 @@ public:
     int rowCount(const QModelIndex &parent = QModelIndex()) const override;
 
     int columnCount(const QModelIndex &parent = QModelIndex()) const override;
-    int filterCount() const;
+    size_t filterCount() const;
     QVariant headerData(int section, Qt::Orientation orientation, int role = Qt::DisplayRole) const override;
     QVariant data(const QModelIndex &index, int role = Qt::DisplayRole) const override;
     bool setData(const QModelIndex& index, const QVariant& value, int role = Qt::EditRole) override;
@@ -86,7 +86,7 @@ public:
     void setQuery(const sqlb::Query& query);
 
     void setChunkSize(size_t chunksize);
-    size_t chunkSize() { return m_chunkSize; };
+    size_t chunkSize() { return m_chunkSize; }
     void sort(int column, Qt::SortOrder order = Qt::AscendingOrder) override;
     void sort(const std::vector<sqlb::SortedColumn>& columns);
     sqlb::ObjectIdentifier currentTableName() const { return m_query.table(); }
@@ -116,7 +116,7 @@ public:
     void addCondFormat(int column, const CondFormat& condFormat);
     void setCondFormats(int column, const QVector<CondFormat>& condFormats);
 
-    DBBrowserDB& db() { return m_db; };
+    DBBrowserDB& db() { return m_db; }
 
 public slots:
     void updateFilter(int column, const QString& value);
diff --git a/src/tests/TestImport.cpp b/src/tests/TestImport.cpp
index 30e09b4f..f9e5d5a8 100644
--- a/src/tests/TestImport.cpp
+++ b/src/tests/TestImport.cpp
@@ -83,13 +83,13 @@ void TestImport::csvImport_data()
     result.append(QVector<QByteArray>() << "g" << "h" << "i");
     QTest::newRow("commas_noquotes") << "a,b,c\nd,e,f\ng,h,i\n"
                                      << ','
-                                     << (char)0
+                                     << static_cast<char>(0)
                                      << "UTF-8"
                                      << 3
                                      << result;
     QTest::newRow("semicolons_noquotes") << "a;b;c\nd;e;f\ng;h;i\n"
                                          << ';'
-                                         << (char)0
+                                         << static_cast<char>(0)
                                          << "UTF-8"
                                          << 3
                                          << result;
@@ -107,13 +107,13 @@ void TestImport::csvImport_data()
                                            << result;
     QTest::newRow("windowslinebreaks") << "a,b,c\r\nd,e,f\r\ng,h,i\r\n"
                                        << ','
-                                       << (char)0
+                                       << static_cast<char>(0)
                                        << "UTF-8"
                                        << 3
                                        << result;
     QTest::newRow("oldmaclinebreaks")  << "a,b,c\rd,e,f\rg,h,i\r"
                                        << ','
-                                       << (char)0
+                                       << static_cast<char>(0)
                                        << "UTF-8"
                                        << 3
                                        << result;
@@ -126,7 +126,7 @@ void TestImport::csvImport_data()
     result.append(QVector<QByteArray>() << "" << "" << "f");
     QTest::newRow("emptyvalues") << "a,b,\nc,\nd,,e\n\n,,f"
                                      << ','
-                                     << (char)0
+                                     << static_cast<char>(0)
                                      << "UTF-8"
                                      << 3
                                      << result;
@@ -135,7 +135,7 @@ void TestImport::csvImport_data()
     result.append(QVector<QByteArray>() << "a" << "b" << "c");
     QTest::newRow("oneline") << "a,b,c"
                              << ','
-                             << (char)0
+                             << static_cast<char>(0)
                              << "UTF-8"
                              << 3
                              << result;
@@ -155,7 +155,7 @@ void TestImport::csvImport_data()
     QString csv = QString::fromUtf8("\xC2\xAE") + "," + QString::fromUtf8("\xC9\x85") + "," + QString::fromUtf8("\xC6\x89") + "\n";
     QTest::newRow("utf8chars") << csv
                                << ','
-                               << (char)0
+                               << static_cast<char>(0)
                                << "UTF-8"
                                << 3
                                << result;
@@ -165,7 +165,7 @@ void TestImport::csvImport_data()
     QString csv2 = QString::fromUtf8("\u4E18") + "," + QString::fromUtf8("\u4E26") + "," + QString::fromUtf8("\u4E4B") + "\n";
     QTest::newRow("utf16chars") << csv2
                                << ','
-                               << (char)0
+                               << static_cast<char>(0)
                                << "UTF-16"
                                << 3
                                << result;