Unable to insert values in database The resulting value is out of range for the DECIMAL / NUMERIC data type (3.1)

Question

When I run my code, It works even shows this error:

java.sql.SQLDataException: The resulting value is out of range for the DECIMAL / NUMERIC data type (3.1).

My Java file:

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.SQLException;
import java.util.Scanner;

public class Aula4 {
    public static void main (String[] args) throws ClassNotFoundException, SQLException {
        try {
            Class.forName("org.apache.derby.jdbc.ClientDriver");
            
            String url = "jdbc:derby://localhost:1527/sistema_academico";
            
            String usuario = "app";
            String senha = "app";
            Connection conexao;
            Scanner ler = new Scanner(System.in);
            conexao = DriverManager.getConnection(url, usuario, senha);
            int id_aluno;
            double nota;
            String nome = null;
            
            System.out.println("Welcome, type your id: ");
            id_aluno = ler.nextInt();
            
            System.out.println("Now, do you need to type your name: ");
            nome = ler.next();
            
            System.out.println("And finally, type your grade:  ");
            nota = ler.nextDouble();
            
            String SQL_Update = "UPDATE aluno set NOTA=? WHERE id_aluno=?";
            String sql = "insert into aluno " +
                  "(id_aluno,nome, nota) " +
                  "values (?,?,?)";
            PreparedStatement stmt = conexao.prepareStatement(sql);
            stmt.setInt(1, id_aluno);
            stmt.setString(2, nome);
            stmt.setDouble(3, nota);
            stmt.executeUpdate();
            stmt.execute();
            stmt.close();
            System.out.println("Accomplished!!");
            
            stmt = conexao.prepareStatement(sql);
            
            }
             catch (SQLException ex){
            System.out.println("Conection failed!"+ex);
        } 
    }
}

I can type all inputs, but in the end, the program displays the error above. I want to insert values into my database, just this error It's disturbing me.

Answer 1

stmt.execute(); is too much, and indeed might have caused an "erroneous" error. The last stmt = conexao.prepareStatement(sql); too.

The MySQL reference might help. DECIMAL(3, 1) has range -9.9 .. 9.9. This might a correct scale, otherwise you maybe intended DECIMAL(5, 2).

nota might be checked.

As floating point (double) is imprecise, it might even be better to use BigDecimal (fixed point) on java side.

        System.out.println("And finally, type your grade:  ");
        BigDecimal bdnota = ler.nextBigDecimal();

        // Check input: scale and digits
        System.out.println("Scale: " + bdnota.scale());

        stmt.setBigDecimal(3, bdnota);