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SQL connection busy although it's already closed

My SQL connection keeps saying it's busy even though all previous connections are closed.
The error below results. All others are either closed by the exiting of the JFrame or the .close() method. Does anyone see anything wrong with the class? (All other classes work as intended.)
SEVERE: null
org.sqlite.SQLiteException: [SQLITE_BUSY] The database file is locked (database is locked)
at org.sqlite.core.DB.newSQLException(DB.java:941)
at org.sqlite.core.DB.newSQLException(DB.java:953)
at org.sqlite.core.DB.execute(DB.java:854)
at org.sqlite.core.DB.executeUpdate(DB.java:895)
package teacherreviewproject;
//initialise imports
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.swing.JOptionPane;
public class FeedbackForm extends javax.swing.JFrame {
//init. variables
String WWW;
String EBI;
int rating;
String teacher;
String studentUser;
String ratingraw;
String teacherQuery;
public FeedbackForm(String s) {
initComponents();
getTeachersNames();
this.studentUser = s;
}
private void getTeachersNames(){
//get the connection
Connection con = DBConnection.getConnection();
//set up query string
this.teacherQuery = "SELECT * FROM users WHERE type=2";
try {
//prepare statement
PreparedStatement teacherState = con.prepareStatement(teacherQuery);
//execute query
ResultSet teachResult = teacherState.executeQuery();
//clear previous items to avoid duplicates.
jComboBox_teachers.removeAllItems();
//create counter variable to get different teachers in RS
int i = 0;
//while loop
while(teachResult.next()){
//get username then add it to position i at combobox
String tempOption = teachResult.getString("username");
System.out.println(tempOption);
jComboBox_teachers.addItem(tempOption); //thanks mcalpine
//increment i
i++;
}
} catch (SQLException ex) {
Logger.getLogger(FeedbackForm.class.getName()).log(Level.SEVERE, null, ex);
}

Found the bug! I needed to make a close-if feature on my Connection class.
Here's the code, should anyone want it:
public class DBConnection{
public static Connection con = null;
public static Connection getConnection(){
//initialise connection
try{
//creates valid url to access DB with
String url = "jdbc:sqlite:" + System.getProperty("user.dir") + "/TeacherReviewIA.DB";
if(con == null){
con = (Connection) DriverManager.getConnection(url);
}else{
con.close();
con = (Connection) DriverManager.getConnection(url);
}
//as a debug measure and to show connection given
System.out.println(con);
}
catch(SQLException ex){
JOptionPane.showMessageDialog(null,ex,"WARNING",JOptionPane.WARNING_MESSAGE);
}
//allows code that called method to use connection given
return con;
}
}

why do I get the error massage java.lang.RuntimeException: java.sql.SQLException: No database selected in my java code(linking with mysql database) [closed]

Closed. This question needs debugging details. It is not currently accepting answers.
Edit the question to include desired behavior, a specific problem or error, and the shortest code necessary to reproduce the problem. This will help others answer the question.
Closed 1 year ago.
Improve this question
package persistentie;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.List;
import domein.Speler;
public class SpelerMapper {
private List<Speler> spelers = new ArrayList<>();
private List<Integer> scoreSpeler = new ArrayList<>();
private static final String UPDATE_SCORE = "insert into ID343589_g52.scoreSpeler(spelerNr,score) values(?,?)";
public SpelerMapper() {
try (Connection conn = DriverManager.getConnection(Connectie.JDBC_URL);
PreparedStatement query = conn.prepareStatement("SELECT * FROM ID343589_g52.speler");
ResultSet rs = query.executeQuery()) {
while (rs.next()) {
String gebruikersnaam = rs.getString("gebruikersNaam");
String wachtwoord = rs.getString("wachtwoord");
spelers.add(new Speler(gebruikersnaam, wachtwoord));
}
} catch (SQLException ex) {
throw new RuntimeException(ex);
}
}
public boolean correcteGegevens(Speler nieuweSpeler) {
return spelers.contains(nieuweSpeler);
}
public List<Integer> geefscoreSpeler(String naam) {
scoreSpeler.clear();
try (Connection conn = DriverManager.getConnection(Connectie.JDBC_URL);
PreparedStatement query = conn.prepareStatement(String.format("SELECT sc.score FROM ID343589_g52.scoreSpeler sc join speler s on s.spelernr = sc.spelerNr where s.gebruikersNaam = '%s'", naam));
ResultSet rs = query.executeQuery()) {
while (rs.next()) {
int score = rs.getInt("score");
scoreSpeler.add(score);
}
} catch (SQLException ex) {
throw new RuntimeException(ex);
}
return scoreSpeler;
}
public void slaScoreOp(int score, String naam) {
try (Connection conn = DriverManager.getConnection(Connectie.JDBC_URL);
PreparedStatement query = conn.prepareStatement(String.format("SELECT sc.score FROM ID343589_g52.scoreSpeler sc join speler s on s.spelernr = sc.spelerNr where s.gebruikersNaam = '%s'", naam));
ResultSet rs = query.executeQuery()) {
int id = 0;
while (rs.next()) {
id = rs.getInt("score");
}
PreparedStatement update = conn.prepareStatement(UPDATE_SCORE);
update.setInt(1, id);
update.setInt(2, score);
update.executeUpdate();
} catch (SQLException ex) {
throw new RuntimeException(ex);
}
}
}
anything stupid I am doing here that is realy not how it working? I am really new to connecting a database with my java projects? the thing that I am trying to do in methode geefScoreSpeler() is getting the scores of an idividual player. and in methode slaScoreOp() I am trying to insert a new column in a table (also trying to get the id of the username via a table that innerjoins)

Hey there I made a user management system and this is my DAO(Databases connection class)
I have used prepared statement in this to see if it might help.
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.SQLException;
import java.sql.Statement;
import com.ums.beans.ems.Employee;
public class EmployeeDao {
Connection connection;
Statement statement;
public EmployeeDao() throws ClassNotFoundException, SQLException {
Class.forName("com.mysql.cj.jdbc.Driver");
connection = DriverManager.getConnection("jdbc:mysql://localhost:3306/user_1", "root", "apaar121");
}
public int saveEmployee(Employee employee) throws SQLException {
String query = "INSERT INTO user_1.employee ('name','dob','address','phone','email','education','designation','salary')VALUES (?,?,?,?,?,?,?,?);";
PreparedStatement preparedStatement = connection.prepareStatement(query);
preparedStatement.setString(1,employee.getName());
preparedStatement.setString(2,employee.getAddress());
preparedStatement.setString(3,employee.getDesignation());
preparedStatement.setString(4,employee.getDob());
preparedStatement.setString(5,employee.getEducation());
preparedStatement.setString(6,employee.getEmail());
preparedStatement.setString(7,employee.getPhone());
preparedStatement.setFloat(8,employee.getSalary());
return preparedStatement.executeUpdate();
}
}

Netbeans MySQL Connection - not to do with jbdc

I have a login app that needs to connect to a server to check the username and password. I am using netbeans and the jbdc is installed and working in the services tab(thanks stack overflow!). By the jbdc is work I mean that i can execute SQL script through it.
I have set this up with MS Server 16 and MySQL so I am convied it is the code:
Connection method:
package dbUtil;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;
public class dbConnection {
private static final String USERNAME = "root";
private static final String PASSWORD = "mess";
private static final String SQCONN = "jdbc:mysql://localhost:1434/MessyLogin?zeroDateTimeBehavior=convertToNull";
public static Connection getConnection()throws SQLException{
try {
Class.forName("com.mysql.jdbc.Driver");
return DriverManager.getConnection(SQCONN, USERNAME, PASSWORD);
}catch (ClassNotFoundException e) {
}
return null;
}
}
loginmodel:
package LogIn;
import dbUtil.dbConnection;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.logging.Level;
import java.util.logging.Logger;
public class LogInModel {
Connection connection;
public LogInModel() {
try{
this.connection = dbConnection.getConnection();
}catch(SQLException e){
}
if(this.connection == null){
System.out.println("here");
// System.exit(1);
}
}
public boolean isDatabaseConnected(){
return this.connection != null;
}
public boolean isLogin(String username, String password) throws Exception{
PreparedStatement pr = null;
ResultSet rs = null;
String sql = "SELECT * FROM MessyLogin where username = ? and Password = ?";
try{
pr = this.connection.prepareStatement(sql);
pr.setString(1, username);
pr.setString(2, password);
rs = pr.executeQuery();
boolean bool1;
if(rs.next()){
return true;
}
return false;
}
catch(SQLException ex){
return false;
}
finally {
{
pr.close();
rs.close();
}
}
}
}
I believe the issue is the return null; from the dbConnection file. The if(this.connection==Null) comes back true and the system is exiting.
Thank you in advance.

Your dbConnection class is a bad idea. Why hard wire those values when you can pass them in?
Your application will only have one Connection if you code it this way. A more practical solution will use a connection pool.
Learn Java coding standards. Your code doesn't follow them; it makes it harder to read and understand.
Here's a couple of recommendations:
package dbUtil;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;
public class dbConnection {
public static final String DRIVER = "com.mysql.jdbc.Driver";
public static final String USERNAME = "root";
public static final String PASSWORD = "mess";
public static final String URL = "jdbc:mysql://localhost:1434/MessyLogin?zeroDateTimeBehavior=convertToNull";
public static Connection getConnection(String driver, String url, String username, String password) throws ClassNotFoundException, SQLException {
Class.forName(driver);
return DriverManager.getConnection(url, username, password);
}
}
I might write that LogInModel this way:
package LogIn;
import dbUtil.dbConnection;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.logging.Level;
import java.util.logging.Logger;
public class LogInModel {
private static final String sql = "SELECT * FROM MessyLogin where username = ? and Password = ?";
private Connection connection;
public LogInModel(Connection connection) {
this.connection = connection;
}
public boolean isLogin(String username, String password) {
boolean isValidUser = false;
PreparedStatement pr = null;
ResultSet rs = null;
try {
pr = this.connection.prepareStatement(sql);
pr.setString(1, username);
pr.setString(2, password);
rs = pr.executeQuery();
while (rs.hasNext()) {
isValidUser = true;
}
} catch (SQLException ex) {
e.printStackTrace();
isValidUser = false;
} finally {
dbUtils.close(rs);
dbUtils.close(pr);
}
return isValidUser;
}
}
Here's my guess as to why your code fails: You don't have the MySQL JDBC driver JAR in your runtime CLASSPATH. There's an exception thrown when it can't find the driver class, but you didn't know it because you swallowed the exception.

Writing data into MySQL table with JavaFX

I have linked up a database to my Java application using the JDBC in Netbeans.
But whenever I try to write something from a TextField to a MySQL table, it doesn't work.
I have a pre-made class to make the database connection.
Here is my database class:
package testswitch;
import java.sql.Connection;
import java.sql.Driver;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.Enumeration;
import java.util.logging.Level;
import java.util.logging.Logger;
/**
*
* #author Maarten
*/
public class Database {
public final static String DB_DRIVER_URL = "com.mysql.jdbc.Driver";
public final static String DB_DRIVER_PREFIX = "jdbc:mysql://";
private Connection connection = null;
public Database(String dataBaseName, String serverURL, String userName, String passWord) {
try {
// verify that a proper JDBC driver has been installed and linked
if (!selectDriver(DB_DRIVER_URL)) {
return;
}
if (serverURL == null || serverURL.isEmpty()) {
serverURL = "localhost:3306";
}
// establish a connection to a named Database on a specified server
connection = DriverManager.getConnection(DB_DRIVER_PREFIX + serverURL + "/" + dataBaseName, userName, passWord);
} catch (SQLException eSQL) {
logException(eSQL);
}
}
private static boolean selectDriver(String driverName) {
// Selects proper loading of the named driver for Database connections.
// This is relevant if there are multiple drivers installed that match the JDBC type.
try {
Class.forName(driverName);
// Put all non-prefered drivers to the end, such that driver selection hits the first
Enumeration<Driver> drivers = DriverManager.getDrivers();
while (drivers.hasMoreElements()) {
Driver d = drivers.nextElement();
if (!d.getClass().getName().equals(driverName)) {
// move the driver to the end of the list
DriverManager.deregisterDriver(d);
DriverManager.registerDriver(d);
}
}
} catch (ClassNotFoundException | SQLException ex) {
logException(ex);
return false;
}
return true;
}
public void executeNonQuery(String query) {
try (Statement statement = connection.createStatement()) {
statement.executeUpdate(query);
} catch (SQLException eSQL) {
logException(eSQL);
}
}
public ResultSet executeQuery(String query) {
Statement statement;
try {
statement = connection.createStatement();
ResultSet result = statement.executeQuery(query);
return result;
} catch (SQLException eSQL) {
logException(eSQL);
}
return null;
}
private static void logException(Exception e) {
System.out.println(e.getClass().getName() + ": " + e.getMessage());
e.printStackTrace();
}
}
And here's my JavaFX controller.
What I want is that when the "handle" button is pressed, that the data filled in the TextField gets inserted into the database.
package testswitch;
import java.io.IOException;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import javafx.event.ActionEvent;
import javafx.fxml.FXML;
import javafx.scene.control.Button;
import javafx.scene.control.CheckBox;
import javafx.scene.control.TextField;
import javafx.stage.Stage;
import testswitch.Database;
/**
*
* #author Maarten
*/
public class gebruikerToevoegenController {
//TextFields
#FXML
private TextField FXVoornaam, FXTussenvoegsel, FXAchternaam, FXGebruikersnaam;
#FXML
private TextField FXWachtwoord, FXEmail, FXTelefoonnummer;
//Boolean checkbox positie
#FXML
private CheckBox ManagerPosition;
#FXML
private Button gebruikerButton;
public final String DB_NAME = "testDatabase";
public final String DB_SERVER = "localhost:3306";
public final String DB_ACCOUNT = "root";
public final String DB_PASSWORD = "root";
Database database = new Database(DB_NAME, DB_SERVER, DB_ACCOUNT, DB_PASSWORD);
public void handle(ActionEvent event) throws SQLException {
String query = "INSERT INTO testDatabase.Gebruikers (Voornaam) VALUES " + FXVoornaam.getText();
try {
database.executeQuery(query);
} catch (Exception e) {
}
}
}
Thanks in advance

The string in your SQL query doesn't seem to be properly quoted. It's best to use PreparedStatement for this scenario:
public class Database {
public PreparedStatement prepareStatement(String query) throws SQLException {
return connection.prepareStatement(query);
}
...
public void handle(ActionEvent event) throws SQLException {
String query = "INSERT INTO testDatabase.Gebruikers (Voornaam) VALUES (?);";
PreparedStatement statement = database.prepareStatement(query);
try {
statement.setString(1, FXVoornaam.getText());
statement.executeUpdate();
} catch (Exception e) {
// log info somewhere at least until it's properly tested/
// you implement a better way of handling the error
e.printStackTrace(System.err);
}
}

You have to add like this in JavaFx :
String query = "INSERT INTO testDatabase.Gebruikers (Voornaam) VALUES ('{FXVoornaam.getText()}') ";

String query = "INSERT INTO testDatabase.Gebruikers(Voornaam)
VALUES('" + FXVoornaam.getText() + "')";

Retrieve values from database to jradiobutton

I'm trying to implement a payroll system and I got some issues with the updating employees. I have stored the gender of the employees as a varchar in my DB. When I type in the employee id and click search button I want to get that info out of the database and display it in a male/female radio buttons according to the data. There are no errors in the code. but the problem is when I try to do that only male button appear selected which is by the way the default. Female radio button doesn't get selected even when the the data on the DB says Female. Can anybody please help me with this issue? below is my code.
package AppPackage;
import static AppPackage.AddEmployeeGUI.convertUtilDateToSqlDate;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.swing.ImageIcon;
import javax.swing.JOptionPane;
public class UpdateEmployeeGUI extends javax.swing.JFrame {
Connection conn=null;
PreparedStatement pst=null;
ResultSet rs=null;
public UpdateEmployeeGUI() {
initComponents();
conn=MySQLConnect.ConnectDb();
}
private void SearchButtonActionPerformed(java.awt.event.ActionEvent evt) {
try {
String sql = "SELECT * FROM EmployeeInfo WHERE EmployeeID =?";
pst=conn.prepareStatement(sql);
pst.setString(1,EmployeeIDSearchField.getText());
rs = pst.executeQuery();
if(rs.next()) {
String ID = rs.getString("EmployeeID");
EmployeeIDField.setText(ID);
String FN = rs.getString("FirstName");
FirstNameField.setText(FN);
String LN = rs.getString("LastName");
LastNameF.setText(LN);
String GN = rs.getString("Gender");
if (GN =="Female"){
MaleRadio.setSelected(false);
FemaleRadio.setSelected(true);
}
else{
FemaleRadio.setSelected(false);
MaleRadio.setSelected(true);
}
String CN = rs.getString("ContactNo");
ContactNoField.setText(CN);
String EM = rs.getString("Email");
EmailField.setText(EM);
SimpleDateFormat date = new SimpleDateFormat("yyyy-MM-dd");
Date dateValue = null;
try {
dateValue = date.parse(rs.getString("DateOfJoin"));
} catch (Exception ex) {
JOptionPane.showMessageDialog(null, ex);
}
jDateChooser.setDate(dateValue);
String Des = rs.getString("Designation");
DesignationComboBox.addItem(Des); //getItemAt(int index);
String BS = rs.getString("BasicSalary");
BasicSalaryField.setText(BS);
}
} catch (SQLException e ) {
JOptionPane.showMessageDialog(null, e);
}
}
private void UpdateEmployeeButtonActionPerformed(java.awt.event.ActionEvent evt) {
// UPDATE EmployeeInfo SET FirstName='?', LastName='?', LastName='?', Gender='?', ContactNo='?',Email='?', DateOfJoin='?', Designation='?' WHERE EmployeeID='?';
try{
String sql1 = "UPDATE EmployeeInfo SET FirstName=?, LastName=?, Gender=?, ContactNo=?, Email=?, DateOfJoin=?, Designation=?, BasicSalary=? WHERE EmployeeID=?";
pst=conn.prepareStatement(sql1);
pst.setString(1,FirstNameField.getText());
pst.setString(2,LastNameF.getText());
pst.setString(3,GenderC);
pst.setString(4,ContactNoField.getText());
pst.setString(5,EmailField.getText());
pst.setDate(6,convertUtilDateToSqlDate(jDateChooser.getDate()));
pst.setString(7,DesignationComboBox.getSelectedItem().toString());
pst.setString(8,BasicSalaryField.getText());
pst.setString(9,EmployeeIDField.getText());
pst.execute();
String sql2 = "UPDATE employeebasicsalary SET BasicSalary=? WHERE EmployeeID=?";
pst=conn.prepareStatement(sql2);
pst.setString(1,BasicSalaryField.getText());
pst.setString(2,EmployeeIDField.getText());
pst.execute();
JOptionPane.showMessageDialog(null, "Successfully updated!");
}catch(Exception e){
JOptionPane.showMessageDialog(null, e);
}
}
private void FemaleRadioActionPerformed(java.awt.event.ActionEvent evt) {
GenderC = "Female";
}
private void MaleRadioActionPerformed(java.awt.event.ActionEvent evt) {
GenderC = "Male";
}
private void ResetButtonActionPerformed(java.awt.event.ActionEvent evt) {
EmployeeIDField.setText(null);
FirstNameField.setText(null);
LastNameF.setText(null);
MaleRadio.setSelected(true);
FemaleRadio.setSelected(false);
ContactNoField.setText(null);
EmailField.setText(null);
jDateChooser.setCalendar(null);
BasicSalaryField.setText(null);
DesignationComboBox.setSelectedIndex(0);
}

replace the lines
if (GN =="Female"){
MaleRadio.setSelected(false);
FemaleRadio.setSelected(true);
}
else{
FemaleRadio.setSelected(false);
MaleRadio.setSelected(true);
}
with
if (GN.equals("Female")){
MaleRadio.setSelected(false);
FemaleRadio.setSelected(true);
} else {
FemaleRadio.setSelected(false);
MaleRadio.setSelected(true);
}
as == is used to compare the hash and values & .equals is used to check the values only..