JDBC several pits

pit 1. Guide pack

 If MySQL Version of 5.0.x, Then the guide package must guide 5.0 My bag 

 yes 8.0.x Direct 8.0 My bag 

 Otherwise, an error will be reported during operation .

I don't know what version I am ？
cmd after , Enter your own mysql

---

pit 2—— function

		// If MySQL yes 5.0 edition , There is no middle cj
		Class.forName("com.mysql.cj.jdbc.Driver");
		
		// If it is 5.0, You don't have to add it ?serverTimezone=GMT;
		// Otherwise, it must be added , Otherwise an error 
        Connection connection = DriverManager.getConnection(
        "jdbc:mysql://localhost:3306/gyp2021?serverTimezone=GMT", "root", "******");
        
        Statement statement = connection.createStatement();
        
        // This statement depends on the specific situation 
        String sql = "update account set balance=100 where id=1";
        
        int i = statement.executeUpdate(sql);
        
        System.out.println(i);