JDBC connection database

Main steps ：
1、 Load database driver
2、 Get database connection （ It includes getting user information 、url）
3、 Create execution sql The object of
4、 perform sql sentence
5、 Returns the result set of the execution
6、 Release the connection

package com.hyc.study01;

import java.sql.*;

public class JdbcFirstDemo {
    
    public static void main(String[] args) throws ClassNotFoundException, SQLException {
    
        //1、 Load database driver 
        Class.forName("com.mysql.jdbc.Driver");

        //2、 Get user information 、url
        //jdbcstudy Is the name of the database to connect to 
        //useUnicode=true&characterEncoding=utf8&useSSL=true  Support Chinese coding & Set the Chinese character set to utf8& Using secure connections 
        String url = 
    "jdbc:mysql://localhost:3306/jdbcstudy?useUnicode=true&characterEncoding=utf8&useSSL=true";
        String username = "root";
        String psw = "123456";

        //3、 Get database connection 
        // there Connection It represents the database , If the returned object is not empty , On behalf of the database, you get 
        Connection connection = DriverManager.getConnection(url, username, psw);

        //4、 Created to perform sql The object of 
        Statement statement = connection.createStatement();

        //5、 perform sql sentence 
        //6、 Return execution result set 
        String sql = "SELECT * FROM users";
        // Execute the query sql sentence , Get the returned result set 
        ResultSet resultSet = statement.executeQuery(sql);// The returned result set is in the form of a linked list 
        while (resultSet.next()) {
    
            System.out.println("id=" + resultSet.getInt("id"));
            System.out.println("name=" + resultSet.getString("NAME"));
            System.out.println("psw=" + resultSet.getString("PASSWORD"));
            System.out.println("email=" + resultSet.getString("email"));
            System.out.println("birth=" + resultSet.getDate("birthday"));
            System.out.println("=====================================================");
        }
        //int num = statement.executeUpdate("add delete update sql"); 
		// All additions, deletions and modifications are used statement.executeUpdate(), This method returns the execution sql The number of lines affected by the statement 

        //7、 Release the connection 
        resultSet.close();
        statement.close();
        connection.close();

    }
}

Database and database tables ：