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Insert query not executing

I want to insert the product the user selected into a table called cart which has two columns: cart_id and item_id_FK both are foreign keys. User_id and id are passed in the constructor and then inserted into cart_id and item_id_fk.
No errors are showing in the code, I double checked the connection username and password, everything works fine except for the cart table.
I tried putting a try and catch statement inside and repeating the steps it didn't work.
if (e.getSource()==AddToCartBtn)
{
//Check to see if item is available
String SizeSelection;
SizeSelection = SizeCmbx.getSelectedItem().toString();
String DBURL ="JDBC:MySql://localhost:3306/shoponline?useSSL=true";
String USER ="root";
String PASSWORD ="12345678";
try {
Connection con = DriverManager.getConnection(DBURL, USER, PASSWORD);
String sql2 = String.format("select itemid,size,productid_fk from items where size='%s' and productid_fk=%d",SizeSelection,id);
PreparedStatement statement = con.prepareStatement(sql2);
ResultSet result = statement.executeQuery(sql2);
String sql3 = "insert into cart (CartID, ItemID_FK)" + " values (?, ?)";
PreparedStatement preparedStmt = con.prepareStatement(sql3);
preparedStmt.setInt(1, user_ID);
preparedStmt.setInt(2, id);
if(result.next())
{
//if item is available
// execute the preparedstatement
preparedStmt.execute();
}//end if
con.close();
}// end try
catch (SQLException ex){
ex.printStackTrace();
}//end catch

Change executeQuery to executeUpdate:
executeQuery(sql3)
to
executeUpdate(sql3)
I believe integers don't need the ' ' around them to be inserted, you may try removing those as well. It may be mistaking them as characters or something similiar.
Otherwise if neither of those above fixes work, try something like this:
String query = "insert into cart (CartID, ItemID_FK)"
+ " values (?, ?)";
// create the mysql insert preparedstatement
PreparedStatement preparedStmt = conn.prepareStatement(query);
preparedStmt.setInt(1, xInt);
preparedStmt.setInt(2, yInt);
// execute the preparedstatement
preparedStmt.execute();
conn.close();

How to add variable value into mysql statement?

I'm learning to work with mysql database and now trying to populate statement with text from textfield.
The program is phone book and strings are name, surname and telephone number which must be writen in textfield and then added to statement for import in database.
So, for now I have this, but not working because statement dont even recognize strings as value.. any ideas what to use/write?
if("Potvrdi".equals(buttonLabel)) {
String ime = a.getText();
String prezime = b.getText();
String broj = c.getText();
Connection conn = dc.connect();
Statement st = (Statement) conn.createStatement();
st.executeUpdate("INSERT INTO imenik VALUES (ime,prezime,broj)");
conn.close();
}

Using prepare statement,
String insertTableSQL = "INSERT INTO imenik VALUES (?,?,?)";
PreparedStatement preparedStatement = conn.prepareStatement(insertTableSQL);
preparedStatement.setString(1, ime);
preparedStatement.setString(2, prezime);
preparedStatement.setString(3, broj);
// execute insert
preparedStatement .executeUpdate();

Number of columns for result set error in SQL database for Java app

I'm having an issue with adding data to a sql database through Java on Netbeans.
String bladeSerial;
String bladeType;
LocalTime startTime1;
private void startButton2ActionPerformed(java.awt.event.ActionEvent evt) {
Connection conn = null;
Statement st = null;
try {
conn = DriverManager.getConnection ("jdbc:derby://localhost:1527/db01", "Administrator", "admin"); //run procedure getConnection to connect to the database - see below
st = conn.createStatement(); //set up a statement st to enable you to send SQL statements to the database.
} catch (SQLException ex) {
Logger.getLogger(FormTwo1.class.getName()).log(Level.SEVERE, null, ex);
}
System.out.println ("Successful Connection");
String query = "insert into TB01(SERIAL,BLADETYPE,STARTT1) values ('+bladeSerial+', '+itemText+', '+(String.valueOf(startTime1))+')";
try (PreparedStatement pstmt = conn.prepareStatement(query)) {
pstmt.setString(1, bladeSerial);
pstmt.setString(2, bladeType);
pstmt.setString(3, String.valueOf(startTime1));
pstmt.executeUpdate();
} catch (SQLException ex) {
Logger.getLogger(FormTwo1.class.getName()).log(Level.SEVERE, null, ex);
}
I get the error The column position '1' is out of range. The number of columns for this ResultSet is '0'.
In the database, Serial is VARCHAR(5), Bladetype is VARCHAR(80)and StartT1 is VARCHAR(12)
The startTime1 variable is saved in the format HH:mm:ss.SSS.
I appreciate any help on this error

You need to give placeholder in your query. Change your code as given here...
String query = "insert into TB01(SERIAL,BLADETYPE,STARTT1) values (?, ?, ?)";
PreparedStatement pstmt = conn.prepareStatement(query);
pstmt.setString(1, bladeSerial);
pstmt.setString(2, bladeType);
pstmt.setString(3, String.valueOf(startTime1));
pstmt.executeUpdate();

You don't need to give column names in query when you are using Prepared statement. Do the following changes:
String query = "insert into TB01(SERIAL,BLADETYPE,STARTT1) values (?, ?, ?)";
Hope it helps!!

Here you are forming query like simple statement and used it in prepared statement which is not possible, so change your query with place holder like below.
String query = "insert into TB01(SERIAL,BLADETYPE,STARTT1) values (?, ?, ?)";
PreparedStatement pstmt = conn.prepareStatement(query);
pstmt.setString(1, bladeSerial);
pstmt.setString(2, bladeType);
pstmt.setString(3, String.valueOf(startTime1));
pstmt.executeUpdate();

If you want to directly use variables names like bladeSerial, then you should use these String variables as if you're adding multiple Strings.
String query = "insert into TB01(SERIAL,BLADETYPE,STARTT1) values ("+bladeSerial+", "+itemText+", "+(String.valueOf(startTime1))+")";
But this is strictly not recommended as it would introduce serious security issues.
The recommended way is to use PreparedStatement. The query you've written is correct, it's just that you have to use placeholders instead of variable names.
String query = "insert into TB01(SERIAL,BLADETYPE,STARTT1) values (?, ?, ?)";
try (PreparedStatement pstmt = conn.prepareStatement(query)) {
pstmt.setString(1, bladeSerial);
pstmt.setString(2, bladeType);
pstmt.setString(3, String.valueOf(startTime1));
pstmt.executeUpdate();
} catch (SQLException ex) {
// Exception handling
Logger.getLogger(FormTwo1.class.getName()).log(Level.SEVERE, null, ex);
}

How to retrieve values from SQL when ID is in array form

The function below will pick the highest value and it will display value which are in column place1(in table placeseen) as output based on the ID.So far I only can get the highest value but not the value in place1.
I don't know what's wrong with my coding because the output is always shows empty.
private void pick_highest_value_here_and_display(ArrayList<Double> value) throws Exception {
// TODO Auto-generated method stub
double aa[]=value.stream().mapToDouble(v -> v.doubleValue()).toArray();
double highest=aa[0+1];
for(int i=0;i<aa.length;i++)
{
if(aa[i]>highest){
highest=aa[i];
String sql ="Select* from placeseen where ID =aa[i]";
DatabaseConnection db = new DatabaseConnection();
Connection conn =db.getConnection();
PreparedStatement ps = conn.prepareStatement(sql);
ResultSet rs = ps.executeQuery();
if (rs.next())
{
String aaa;
aaa=rs.getString("place1");
System.out.println(aaa);
}
ps.close();
rs.close();
conn.close();
}
}
System.out.println(highest);
}

instead of
String sql ="Select * from placeseen where ID =aa[i]";//aa[i] taking a value
use
String sql ="Select place1 from placeseen where ID =?";
PreparedStatement ps = conn.prepareStatement(sql);
ps.setDouble(1, aa[i]);
passing aa[i] variable value .
Avoid sql injection

You can try this
// as you are using preparedStatement you can use ? and then set value for it to prevent sql injection
String sql = "Select * from placeseen where ID = ?";
DatabaseConnection db = new DatabaseConnection();
Connection conn = db.getConnection();
PreparedStatement ps = conn.prepareStatement(sql);
ps.setDouble(1, aa[i]); // 1 represent first attribute represented by ?
System.out.println(ps); // this will print query in console
ResultSet rs = ps.executeQuery();
if (rs.next()) {
System.out.println("Inside rs.next()"); // for debug purpose
String aaa;
aaa=rs.getString("place1");
System.out.println(aaa);
}
// remaining code

Inserting auto generated id in sqllite using java [duplicate]

This question already has an answer here:
How to perform an SQL insert in Java
(1 answer)
Closed 7 years ago.
I am writing java application using sqllite
public Product createProduct(String productName) throws SQLException {
String query = "INSERT into tbl_Product (name) values (?) ";
PreparedStatement preparedStatement = null;
Connection connection = null;
ResultSet rs = null;
Product product = null;
try {
connection = ConnectionFactory.getConnection();
preparedStatement = connection.prepareStatement(query);
//preStatement.setInt(1, 0);
preparedStatement.setString(1, productName);
preparedStatement.executeUpdate();
} finally {
//preparedStatement.close();
DbUtil.close(rs);
DbUtil.close(preparedStatement);
DbUtil.close(connection);
}
return product;
}
My product table have (ID,Name) column, where Id is auto generated. What all java changes are required so that preStatement can insert auto generated id in db.

String query = "INSERT into tbl_Product values (?) ";
ResultSet rs = null;
Product product = null;
try {
connection = ConnectionFactory.getConnection();
preStatement = (PreparedStatement) connection.prepareStatement(query);
preStatement.setString(1, productName);
rs = preStatement.executeQuery();

String sqlQuery = "INSERT into tbl_Product values (?)
PreparedStatement stmt = conn.prepareStatement(sqlQuery);
stmt.setString( 1, "val" ); //nameText variable contains the text of the jtextfield)
stmt.executeUpdate();
use execute update instead of execute query.
executeQuery():
Executes the SQL query in this PreparedStatement object and returns the ResultSet object generated by the query.
executeUpdate():
Executes the SQL statement in this PreparedStatement object, which must be an SQL INSERT, UPDATE or DELETE statement; or an SQL statement that returns nothing, such as a DDL statement.