lab2 supplementary

import java.sql.*;

public class Main {

    private static final String connStr = "jdbc:postgresql://127.0.0.1:5432/dblab";

    private static final String user = "postgres";

    private static final String pass = "123456";

    public static void main(String[] args) {

        try {

            Connection conn = DriverManager.getConnection(connStr, user, pass);

            PreparedStatement statement = conn.prepareStatement("INSERT INTO test(name, grade) VALUES(?,?) RETURNING id;");

            statement.setString(1, "114514");

            statement.setInt(2, 1919810);

            ResultSet resultSet = statement.executeQuery();

            int result = -1;

            while (resultSet.next()) {

                result = resultSet.getInt(1);

            }

            System.out.println("inserted, return id: " + result);

            conn.close();

            testRead(result);

        } catch (SQLException e) {

            e.printStackTrace();

        }

    }

    public static void testRead(int id) throws SQLException {

        Connection conn = DriverManager.getConnection(connStr, user, pass);

        PreparedStatement statement = conn.prepareStatement("SELECT id,name,grade FROM test WHERE id=?;");

        statement.setInt(1, id);

        ResultSet resultSet = statement.executeQuery();

        while (resultSet.next()) {

            int serialID = resultSet.getInt(1);

            String name = resultSet.getString(2);

            int grade = resultSet.getInt(3);

            System.out.printf("id:%d name:%s grade:%d\n", serialID, name, grade);

        }

        conn.close();

    }

}

# Supplementary for Lab 2

Source Code: [Main.java](./Main.java)