Connecting and Querying

import java.sql.*;

public class ProductQuery {
    private static final String URL = "jdbc:mysql://localhost:3306/shopease";

    public static void main(String[] args) {
        String sql = "SELECT id, name, price, stock FROM product WHERE category = ? ORDER BY price";

        // try-with-resources closes ResultSet, Statement and Connection in reverse order
        try (Connection con = DriverManager.getConnection(URL, System.getenv("DB_USER"), System.getenv("DB_PASS"));
             PreparedStatement ps = con.prepareStatement(sql)) {

            ps.setString(1, "Electronics");
            try (ResultSet rs = ps.executeQuery()) {
                while (rs.next()) {
                    System.out.printf("%d %-12s %10.2f %4d%n",
                            rs.getLong("id"), rs.getString("name"),
                            rs.getBigDecimal("price"), rs.getInt("stock"));
                }
            }
        } catch (SQLException e) {
            System.err.println("DB error " + e.getSQLState() + ": " + e.getMessage());
        }
    }
}

java -cp .:mysql-connector-j-8.4.0.jar ProductQuery

7 Cable             199.00  140
2 Charger           899.00   60
3 Earbuds          1999.00   25
1 Phone           15999.00   12

String insert = "INSERT INTO product (name, price, stock, category) VALUES (?, ?, ?, ?)";
try (Connection con = dataSource.getConnection();
     PreparedStatement ps = con.prepareStatement(insert, Statement.RETURN_GENERATED_KEYS)) {
    ps.setString(1, "Smart Watch");
    ps.setBigDecimal(2, new BigDecimal("4999.00"));
    ps.setInt(3, 40);
    ps.setString(4, "Electronics");
    int rows = ps.executeUpdate();                     // INSERT / UPDATE / DELETE
    try (ResultSet keys = ps.getGeneratedKeys()) {
        if (keys.next()) System.out.println(rows + " row inserted, id = " + keys.getLong(1));
    }
}