JavaFX Sqlite Insert with Foreign Key - sqlite

Question

I am currently learning JavaFX and Sqlite.
I have an Sqlite Database which I built with MySQL manager, there are already foreign key rules etc.
For example user and adress:
CREATE TABLE "Benutzer" ("Benutzername" TEXT PRIMARY KEY NOT NULL , "Vorname" VARCHAR, "Nachname" VARCHAR, "Email" TEXT UNIQUE , "Passwort" TEXT, "AdresseID" INTEGER, FOREIGN KEY(AdresseID) REFERENCES Adresse(AdresseID))
CREATE TABLE "Adresse" ("AdresseID" INTEGER PRIMARY KEY NOT NULL , "Land" VARCHAR, "Stadt" VARCHAR, "Straße" TEXT, "Hausnr." INTEGER)
I connected the database to my JavaFX application, now I am trying to create the register function, so a new user is on an fxml template where he can fill in "Benutzername", "Vorname" etc. and his adress "Land", "Stadt" etc.
Here is the form:
Adding these values to the database works, but I do not have an idea how to tell javaFX that this current user which is inserted has to take the current adress which is inserted (its AdressID) as foreign key.
User is inserted without foreign key:
I was reseaching and found things like
mysql_insert_id returns the last auto-increment value generated by the database connection currently in use.
But I dont know how to access it.
Thats my model which I use to fill in the data into my database:
public class RegisterModel {
Connection conection;
// Konstruktor
public RegisterModel() {
conection = SqliteConnection.Connector();
// Wenn die Verbindung nicht erfolgreich ist, dann App schließen
if (conection == null) {
System.out.println("connection not successful");
System.exit(1);
}
}
public boolean isDbConnected() {
try {
return !conection.isClosed();
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
return false;
}
}
public boolean RegisterUser(String user_benutzername, String user_vorname, String user_nachname, String user_email,
String user_passwort, String adress_land, String adress_stadt, String adress_strasse,
String adress_hausnummer) throws SQLException {
PreparedStatement preparedStatement = null;
PreparedStatement preparedStatement_for_adress = null;
// or ignore besprechen
String query = "insert or ignore into Benutzer (Benutzername, Vorname, Nachname, Email, Passwort) values(?,?,?,?,?)";
String query_adress = "insert into Adresse (Land, Stadt, Straße, 'Hausnr.') values(?,?,?,?)";
try {
preparedStatement = conection.prepareStatement(query);
preparedStatement.setString(1, user_benutzername);
preparedStatement.setString(2, user_vorname);
preparedStatement.setString(3, user_nachname);
preparedStatement.setString(4, user_email);
preparedStatement.setString(5, user_passwort);
System.out.println("Benutzer wurde eingefuegt");
preparedStatement_for_adress = conection.prepareStatement(query_adress);
preparedStatement_for_adress.setString(1, adress_land);
preparedStatement_for_adress.setString(2, adress_stadt);
preparedStatement_for_adress.setString(3, adress_strasse);
preparedStatement_for_adress.setString(4, adress_hausnummer);
System.out.println("Adresse wurde eingefügt");
preparedStatement.executeUpdate();
preparedStatement_for_adress.executeUpdate();
return true;
} catch (Exception e) {
e.printStackTrace();
return false;
} finally {
preparedStatement.close();
preparedStatement_for_adress.close();
}
}
}
I think there must be a 3rd query which takes the AdressID of the current adress and assigns it to the current user as his adress? So thats the interessting part:
String query = "insert or ignore into Benutzer (Benutzername, Vorname, Nachname, Email, Passwort) values(?,?,?,?,?)";
String query_adress = "insert into Adresse (Land, Stadt, Straße, 'Hausnr.') values(?,?,?,?)";

Answer 1

You should insert the Address first with a PreparedStatement.
Retrieve the ID (last inserted ID) of the Address, see Java PreparedStatement retrieving last inserted ID
Now insert the User with the AddressId stated in step 2. So you have to include the AddressId column in the user INSERT INTO statement.
Your user insert query should become:
String query = "insert or ignore into Benutzer (Benutzername, Vorname, Nachname, Email, Passwort, AddressId) values(?,?,?,?,?,[put last_inserted_id here)";