Added sql selection menu and updated readme

Currently, only sqlite is supported. Other flavors may follow

README.md

@@ -22,4 +22,4 @@ _To get started you can download a sample file from sqlitetutorial.net [here](ht
 - SQLite
 
 ## Roadmap
-I plan on adding support for more SQL-flavours such as PostgresQL, MySQL and MSSQL in the future.
+I plan on adding support for more SQL-flavours such as MySQL & MSSQL in the future.

app/src/main/java/SQLite/Viewer/Driver.java

@@ -11,19 +11,20 @@
 public class Driver implements AutoCloseable {
 
     private Connection connection;
+    private static String url;
 
+    // Queries
     public static final String SQL_ALL_ROWS = "SELECT * FROM %s;";
     private static final String SQL_FIND_ALL_TABLES =
             "SELECT name FROM sqlite_master WHERE type ='table' AND name NOT LIKE 'sqlite_%';";
 
     public Driver(String fileName) throws SQLException {
+        setUrl();
         connect(fileName);
     }
 
     // Connect to a selected database
     protected void connect(String fileName) throws SQLException {
-        // SQLite default url
-        String url = "jdbc:sqlite:%s";
         SQLiteDataSource dataSource = new SQLiteDataSource();
         dataSource.setUrl(String.format(url, fileName));
         connection = dataSource.getConnection();
@@ -67,6 +68,11 @@ protected DataTableModel runQuery(String query, String table) throws SQLExceptio
         }
     }
 
+    private void setUrl() {
+        // Currently, only sqlite is supported
+        url = "jdbc:sqlite:%s";
+    }
+
     @Override
     public void close() throws Exception {
         connection.close();

app/src/main/java/SQLite/Viewer/SQLiteViewer.java

@@ -16,9 +16,9 @@ public class SQLiteViewer extends JFrame {
     public SQLiteViewer() {
         // Basic window settings
         setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
-        setSize(595, 700);
+        setSize(540, 700);
         setLayout(new BorderLayout());
-        setResizable(true);
+        setResizable(false);
         setLocationRelativeTo(null);
         setTitle("SQLite Viewer");
         // Initialize main window components
@@ -41,8 +41,8 @@ private void initComponents() {
 
         JTextArea queryTextArea = new JTextArea();
         queryTextArea.setName("QueryTextArea");
-        queryTextArea.setRows(5);
-        queryTextArea.setColumns(40);
+        queryTextArea.setRows(8);
+        queryTextArea.setColumns(35);
         queryTextArea.setEnabled(false);
         JScrollPane queryTextScroll = new JScrollPane(queryTextArea);
 
@@ -70,9 +70,7 @@ private void initComponents() {
         JMenuItem quitMenuItem = new JMenuItem("Quit");
         quitMenuItem.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_Q,
                 Toolkit.getDefaultToolkit().getMenuShortcutKeyMaskEx()));
-        quitMenuItem.addActionListener(actionEvent -> {
-            System.exit(0);
-        });
+        quitMenuItem.addActionListener(actionEvent -> System.exit(0));
         quitMenuItem.setName("MenuExit");
 
         // Add file menu components
@@ -83,7 +81,8 @@ private void initComponents() {
         // SQL selection menu
         JMenu sqlMenu = new JMenu("Select");
 
-        JMenuItem sqliteMenuItem = new JMenuItem("SQLite");
+        JCheckBoxMenuItem sqliteMenuItem = new JCheckBoxMenuItem("SQLite");
+        sqliteMenuItem.setState(true);
 
         sqlMenu.add(sqliteMenuItem);
 
@@ -164,9 +163,8 @@ private void initComponents() {
                 );
             }
         });
-        tablesComboBox.addItemListener(actionEvent -> {
-            queryTextArea.setText(String.format(Driver.SQL_ALL_ROWS, actionEvent.getItem().toString()));
-        });
+        tablesComboBox.addItemListener(actionEvent ->
+                queryTextArea.setText(String.format(Driver.SQL_ALL_ROWS, actionEvent.getItem().toString())));
         executeButton.addActionListener(actionEvent -> {
             try (Driver driver = new Driver(fileNameTextField.getText())) {
                 DataTableModel tableModel = driver.runQuery(