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Getting Java mysql SQL Syntax error but my query seems normal

I am developing a simple java mysql based application and during data insertion into the database I'm getting an SQL error mentioned below.
Here is my code:
public DBConnection() {
try {
Class.forName("com.mysql.jdbc.Driver");
con = DriverManager.getConnection("jdbc:mysql://localhost:3306/myDatabase?useUnicode=true&useLegacyDatetimeCode=false&serverTimezone=Turkey", "root", "");
st = con.createStatement();
System.out.println("CONNECTED!");
} catch (Exception e) {
System.out.println("Error : " + e);
}
}
public void addCustomer(String name, String surname, String company, String adress, String adressTwo){
String addQuery = "insert into musteri (name,surname,company,adress,adressTwo) values (?,?,?,?,?)" ;
try {
st.executeUpdate(addQuery);
System.out.println("Data Added");
} catch (Exception e) {
System.out.println("Error occured when adding value to database : " + e );
}
}
Here is my java main method that add's the data:
public static void main(String[] args) {
// TODO code application logic here
Customers c1 = new Customers();
c1.setIsim("test");
c1.setSoyisim("test");
c1.setSirket("test");
c1.setAdres("test");
c1.setIletisim("test");
DBConnection db = new DBConnection();
db.addCustomer(c1.isim, c1.soyisim, c1.sirket, c1.adres, c1.iletisim);
}
The error I'm getting is:
Error occured when adding value to database : java.sql.SQLSyntaxErrorException: You have an error in your SQL syntax; check the manual that corresponds to your MariaDB server version for the right syntax to use near ''insert into musteri (ad,soyad,sirket,adres,iletisim) values (?,?,?,?,?)'' at line 1

You are mixing statements with prepared statements. You should use a prepared statement and set the values to it:
public void addCustomer(String name, String surname, String company, String address, String adressTwo) {
String addQuery = "insert into musteri (name, surname, company, adress, adressTwo) values (?,?,?,?,?)" ;
// Shown here for simplicitly.
// The query could be prepared once and stored in a data member
try (PreparedStatement ps = con.prepareStatement(addQuery)) {
ps.setString(1, name);
ps.setString(2, surname);
ps.setString(3, company);
ps.setString(4, address);
ps.setString(5, addressTwo);
ps.executeUpdate();
System.out.println("Data Added");
} catch (Exception e) {
System.out.println("Error occured when adding value to database : " + e );
}
}

May I suggest you implement addCustomer like this. Use a local Statement and create it by using try-with-resource style and then set your parameters for the query
public void addCustomer(String name, String surname, String company, String adress, String adressTwo){
String addQuery = "insert into musteri (name,surname,company,adress,adressTwo) values (?,?,?,?,?)" ;
try (PreparedStatement stmt = con.prepareStatement(addQuery)) {
stmt.setString(1, name);
stmt.setString(2, surname);
stmt.setString(3, company);
stmt.setString(4, adress);
stmt.setString(5, adressTwo);
stmt.executeUpdate();
System.out.println("Data Added");
} catch (Exception e) {
System.out.println("Error occured when adding value to database : " + e );
}
}

Running executeBatch() from another location

I want to create another method called public void execute() and run the preparedStmt.executeBatch(); from there, but I don't know how.
public void save() {
FacesContext context = FacesContext.getCurrentInstance();
context.addMessage(null, new FacesMessage("Sacuvano nov proizvod sa sifrom: " + proizvodID + " Naziv proizvoda: " + naziv));
try {
String myDriver = "org.gjt.mm.mysql.Driver";
String myUrl = "jdbc:mysql://localhost/fpis";
Class.forName(myDriver);
Connection conn = DriverManager.getConnection(myUrl, "root", "root");
String query = " insert into proizvod values (?, ?, ?, ?, ?)";
PreparedStatement preparedStmt = conn.prepareStatement(query);
preparedStmt.setInt(1, proizvodID);
preparedStmt.setString(2, naziv);
preparedStmt.setString(3, opis);
preparedStmt.setDouble(4, cena);
preparedStmt.setString(5, jedMere);
preparedStmt.addBatch();
preparedStmt.executeBatch();
conn.close();
} catch (Exception e) {
System.err.println("Greska!");
System.err.println(e.getMessage());
}
}
public void execute(){
{

You should declare PreparedStatement preparedStmt and Connection conn as a attribute of your class.
Like that you could setup preparedStmt in public void save() and conn in your constructor. After that, just call preparedStmt.executeBatch(); from public void execute(); and close conn after.

SQL Prepared Statement & returning type

I have just created a method in my class file, were I insert data into my sql database.
1) Are these prepared statements correct?
2) I need to return a type car for the method (Where could this be done)?
.....As the error I get at the moment is the method must return a type Car (Car is the name of the class file)
public Car addVehicle(String aLicense, int aJourneys, String aUsername, String aPassword) {
Car c = new Car();
try {
Class.forName("com.mysql.jdbc.Driver");
Connection conn = DriverManager.getConnection(url + dbName, userName, password);
statement = conn.createStatement();
String query = " insert into eflow.registration (cLicense, cJourneys, cUsername, cPassword)"
+ " values (?, ?, ?, ?)";
PreparedStatement preparedStmt = conn.prepareStatement(query);
preparedStmt.setString(1, aLicense);
preparedStmt.setInt(2, aJourneys);
preparedStmt.setString(3, aUsername);
preparedStmt.setString(4, aPassword);
preparedStmt.execute();
conn.close();
} catch (Exception e) {
System.err.println("Got an exception!");
System.err.println(e.getMessage());
}
return c;
}
Calling the method returns an error that the method is not applicable for arguments
//int addingID = Integer.parseInt(enteringID.getText());
String addingReg = enteringReg.getText();
int addingJourneys = Integer.parseInt(enteringJourneys.getText());
String addingUsername = enteringUsername.getText();
#SuppressWarnings("deprecation")
String addingPassword = enteringPassword.getText();
Car newCar = new Car(addingReg, addingJourneys, addingUsername, addingPassword);
int addStatus = myCar.addVehicle(newCar);
if (addStatus == 1) {
JOptionPane.showMessageDialog(null, "Vehicle Added");
enteringID.setText("(eg. 1-999)");
enteringReg.setText("(eg. - 162-MH-749)");
enteringJourneys.setText("(eg. 7)");
enteringUsername.setText("(eg. - username#domain.com)");
enteringPassword.setText("");
}
else {
JOptionPane.showMessageDialog(null, "Error, Please Try Again");
}
} catch (Exception f) {
JOptionPane.showMessageDialog(null, "Error, Please Try Again");
}
}
});

This is not a final answer for your question, but purely to clarify my comment.
If you want your method to return a Car object, you'll have to create an instance of class Car and return it:
public Car addVehicle(String aLicense, int aJourneys, String aUsername, String aPassword) {
try {
Class.forName("com.mysql.jdbc.Driver");
Connection conn = DriverManager.getConnection(url + dbName, userName, password);
statement = conn.createStatement();
String query = " insert into eflow.registration (cLicense, cJourneys, cUsername, cPassword)"
+ " values (?, ?, ?, ?)";
PreparedStatement preparedStmt = conn.prepareStatement(query);
preparedStmt.setString(1, "'" + aLicense + "'");
preparedStmt.setInt(2, aJourneys);
preparedStmt.setString(3, "'" + aUsername + "'");
preparedStmt.setString(4, "'" + aPassword + "'");
preparedStmt.execute();
conn.close();
Car c = new Car();
//Do anything with the car object that you like.
//for example: c.setColor("blue");
return c;
} catch (Exception e) {
System.err.println("Got an exception!");
System.err.println(e.getMessage());
//kayaman is correct here: we still need to return something here in order to be able to compile
return null;
}

Separate the logic!
Use this class to retrieve connection where you need it:
public class DatabaseConnection
{
private static final String CONN_URL = "some connection url";
private static Connection instance = null;
static
{
try
{
Class.forName("com.mysql.jdbc.Driver");
}
catch (ClassNotFoundException e)
{
e.printStackTrace();
}
}
public static synchronized Connection getInstance() throws SQLException
{
if (instance == null)
{
instance = DriverManager.getConnection(CONN_URL);
}
return instance;
}
}
Use it in your function like this:
public Car addVehicle(String aLicense, int aJourneys, String aUsername, String aPassword)
{
String sql = "insert into eflow.registration (cLicense, cJourneys, cUsername, cPassword) values (?, ?, ?, ?)";
try (Connection conn = DatabaseConnection.getInstance(); PreparedStatement prepStatement = conn.prepareStatement(sql))
{
Car successfulAdd = new Car();
prepStatement.setString(1, aLicense);
prepStatement.setInt(2, aJourneys);
prepStatement.setString(3, aUsername);
prepStatement.setString(4, aPassword);
if (prepStatement.execute())
{
return successfulAdd;
}
}
catch (SQLException e)
{
e.printStackTrace();
}
return null;
}

ORA-02289: sequence does not exist, cannot find my error

public static void main(String[] argv) {
try {
createTable();
insertRecordIntoTable("leo","123");
} catch (SQLException e) {
System.out.println(e.getMessage());
}
}
private static void createTable() throws SQLException {
Connection dbConnection = null;
PreparedStatement preparedStatement = null;
String sequence = "CREATE SEQUENCE ID_SEQ INCREMENT BY 1 MAXVALUE 99999999999999999999 MINVALUE 1 CACHE 20";
String createTableSQL = "CREATE TABLE DBUSER1("
+ "USER_ID NUMBER(5) NOT NULL, "
+ "USERNAME VARCHAR(20) NOT NULL, "
+ "PASSWORD VARCHAR(20) NOT NULL, "
+ "PRIMARY KEY (USER_ID) "
+ ")";
try {
dbConnection = getDBConnection();
preparedStatement = dbConnection.prepareStatement(createTableSQL);
System.out.println(createTableSQL);
// execute create SQL stetement
preparedStatement.executeUpdate(createTableSQL);
preparedStatement.executeUpdate(sequence);
System.out.println("Table \"dbuser\" is created!");
} catch (SQLException e) {
System.out.println(e.getMessage());
} finally {
if (preparedStatement != null) {
preparedStatement.close();
}
if (dbConnection != null) {
dbConnection.close();
}
}
}
private static Connection getDBConnection() {
Connection dbConnection = null;
try {
Class.forName(DB_DRIVER);
} catch (ClassNotFoundException e) {
System.out.println(e.getMessage());
}
try {
dbConnection = DriverManager.getConnection(
DB_CONNECTION, DB_USER,DB_PASSWORD);
return dbConnection;
} catch (SQLException e) {
System.out.println(e.getMessage());
}
return dbConnection;
}
private static void insertRecordIntoTable(String username, String password) throws SQLException {
Connection dbConnection = null;
PreparedStatement preparedStatement = null;
String insertTableSQL = "INSERT INTO DBUSER1"
+ "(USER_ID, USERNAME, PASSWORD) VALUES"
+ "(ID_SEQ.NEXTVAL,?,?)";
try {
dbConnection = getDBConnection();
preparedStatement = dbConnection.prepareStatement(insertTableSQL);
// execute insert SQL stetement
preparedStatement.setString(1, username);
preparedStatement.setString(2, password);
preparedStatement.executeUpdate();
System.out.println("Record is inserted into DBUSER table!");
} catch (SQLException e) {
System.out.println(e.getMessage());
} finally {
if (preparedStatement != null) {
preparedStatement.close();
}
if (dbConnection != null) {
dbConnection.close();
}
}
}
I cannot find the error when I try to create a sequence for my table.
When I try to insert some data in my table with the sequence it says it doesn't exist, but I did create it. Also I am not sure if i need a preparedStatement.setInt(1, seq_id.nextval); it gives an error but im not quite sure how I would do this

The solution might be adding the schema name (owner) before the name of sequence:
CREATE SEQUENCE some_nameOf_schema.ID_SEQ INCREMENT BY 1 MAXVALUE 99999999999999999999 MINVALUE 1 CACHE 20

You're preparing a statement with one SQL text, and executing the statement with two different SQL texts;
preparedStatement = dbConnection.prepareStatement(createTableSQL);
preparedStatement.executeUpdate(createTableSQL);
preparedStatement.executeUpdate(sequence);
...which is actually invalid according to the docs;
int executeUpdate(String sql)
throws SQLException
Executes the given SQL statement, which may be an INSERT, UPDATE, or DELETE statement or an SQL statement that returns nothing, such as an SQL DDL statement.
Note:This method cannot be called on a PreparedStatement or CallableStatement.
What you need to do is to prepare and execute two different statements;
preparedStatement = dbConnection.prepareStatement(createTableSQL);
preparedStatement.executeUpdate();
preparedStatement = dbConnection.prepareStatement(sequence);
preparedStatement.executeUpdate();

In general, it doesn't make much sense to CREATE database objects every time your application starts up, because this is something that's usually done only once, when you install/upgrade the database/schema the application uses.
However, if you really have to do it this way, the current solution could be improved so that the following points are considered:
Only execute the CREATE statements when the objects do not yet exist in the DB. This can be done by first inspecting the USER_OBJECTS data dictionary view.
Use a plain Statement instead of PreparedStatement for executing the DDL (prepared statements are only useful for DML operations that use input variables)
Handle JDBC resources (Connection / Statement / ResultSet) concisely and safely through the try-with-resources construct
Here's how the code could look like:
// query constants
private static final String CHECK_DB_OBJECT =
"SELECT 1 FROM user_objects WHERE object_name = ?";
private static final String CREATE_SEQUENCE =
"CREATE SEQUENCE ID_SEQ INCREMENT BY 1 MAXVALUE 99999999999999999999" +
" MINVALUE 1 CACHE 20";
private static final String CREATE_TABLE = "CREATE TABLE DBUSER1("
+ "USER_ID NUMBER(5) NOT NULL, "
+ "USERNAME VARCHAR(20) NOT NULL, "
+ "PASSWORD VARCHAR(20) NOT NULL, "
+ "PRIMARY KEY (USER_ID) "
+ ")";
/* clip the main method etc. */
/**
* Creates the table and sequence only if they do not already exist.
*/
private static void createTableAndSequenceIfAbsent() {
try (Connection dbConnection = DriverManager.getConnection(
DB_CONNECTION, DB_USER, DB_PASSWORD);
PreparedStatement ps = dbConnection
.prepareStatement(CHECK_DB_OBJECT)) {
if (!dbObjectExists(ps, "ID_SEQ")) {
executeDDL(dbConnection, CREATE_SEQUENCE);
}
if (!dbObjectExists(ps, "DBUSER1")) {
executeDDL(dbConnection, CREATE_TABLE);
}
} catch (SQLException e) {
e.printStackTrace();
}
}
private static boolean dbObjectExists(PreparedStatement ps,
String objectName) throws SQLException {
ps.setString(1, objectName);
ResultSet rs = ps.executeQuery();
// if the #CHECK_DB_OBJECT query returned a row, the object exists
return rs.next();
}
private static void executeDDL(Connection c, String sql)
throws SQLException {
try (Statement st = c.createStatement()) {
st.execute(sql);
}
}

Null pointer exception on insert into database java

Hi I have this method below which should insert values into my database. However I am getting a Null Pointer Exception on the PreparedStatement line
public void insertReservation(String name, String phone, int size, String date, String time, String additionalRequirements, String memberID, String themeID) throws SQLException, ClassNotFoundException {
try {
String strQuery = "INSERT INTO reservation VALUES (?, ? ,?, TO_DATE(?, 'dd-MMM-yy'), ?, ?, ?, ?)";
PreparedStatement stmt = conn.prepareStatement(strQuery);/
stmt.setString(1, name);
stmt.setString(2, phone);
stmt.setInt(3, size);
stmt.setString(4, date);
stmt.setString(5, time);
stmt.setString(6, additionalRequirements);
stmt.setString(7, memberID);
stmt.setString(8, themeID);
results = stmt.executeQuery();
} catch (Exception e) {
e.printStackTrace();
}//end try
}
Am I inserting this correctly into my database? I am not sure why I am getting this null pointer exeception error.

conn is null, print its value.

Don't know but try this
String strQuery = "insert into reservation(ColumnName1, ColumnName2 ,ColumnName3,) values(?,?,?)";
and at the end it will be only execute();
like this stmt.execute();
executeQuery(); statement works with select query Only
Secondly have you described conn value in constructor or method in which ever class you are using the query if you have than assign it like this conn= SqlConnection.ConnecrDb();
below is the SqlConnection Seperate class i have created
public class SqlConnection {
Connection conn=null;
public static Connection ConnecrDb(){
try
{
Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
Connection conn= DriverManager.getConnection("jdbc:odbc:Test","","");
return conn;
}
catch(Exception e)
{
JOptionPane.showMessageDialog(null, e);
return null;
}
}
}
Hope it will help you