//First, some imports. Be careful with the Date and Timestamp imports, there's a java.sql.Date class too:

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.Statement;
import java.sql.SQLException;
import java.sql.Timestamp;
import java.util.Date;


public class DBTest {

// Some variables:

private static final String db_ip = "127.0.0.1";
private static final String db_name = "myDatabase";
private static final String db_user = "username";
private static final String db_pass = "password";

private Connection conn = null;

public void dbTest(){

// Now, to connect:

    try {
    
           conn = DriverManager.getConnection("jdbc:mysql://" + db_ip + ":3306/" + db_name, db_user, db_pass); 
                                                 
    } catch (SQLException e) {
            //do something with the error
    }

    //Now we should have a connection, but it's foot to check that it isn't null, then select some data


    if(conn !=  null){

    //Let's get a list of users who live in the zip code 11111.

    String zipToGet = "11111";

    String userQuery = "SELECT age, user_name, created_on FROM users WHERE zip = " + zipToGet;

    Statement userStatement = conn.createStatement();

    ResultSet userResult = userStatement.exequteQuery(userQuery);

    //Not to scary so far, right? in the userQuery we're saying we want the age, user_name, and created_on fields from the 
    //users table whenever the zip is the one we specified. This is just a MySQL statement.


    //userResult will be null if something went wrong, or if there's just no result.

    if(userResult != null){
         List<User> users = new ArrayList<>(); //hypothetical user class
        while(userResult.hasNext(){
        int age = result.getInt("age");
        String username = result.getString("user_name");
        Date createdOn = result.getTimestamp("created_on"); //This returns a Timestamp, but it can be cast directly into a date

       //Do stuff with this data:
       //Using the hypothetical user class with what data we have

        User user = new User(username); 
        user.age = age;
        user.createDate = createdOn;
        users.add(user);
    }


    for(user : users){
        //do something with the users
    }

    }else{
        //here is where you put code to deal with no result from user query
    }
    }

//Now we'll work on inserting new data into the database. Keep in mind that manipulating that data has no affect on the //database, for that we need to to create another statement:

PreparedStatement insertStatement = null;

String insertString = "INSERT INTO users (user_name, created_on, age) VALUES (?,?,?)";
if(conn != null){

insert = conn.prepareStatement(insertString); //creates the statement

insert.setString(1, "newUserName); // 1 represents the position of the question mark we left in the insertString

Date now = new Date();

insert.setTimestamp(2, new Timestamp(now.getTime()); 

insert.setInt(3, 28);

insert.execute();

insert.close();
}
 
//Now we've selected and inserted, we can also update:

if(conn != null){

String update = "UPDATE users SET age WHERE user_name = 'someUser'"; 
//this assumes usernames are unique, usually would use an id number

Statement updateStatement = conn.createStatement();

updateStatement.execute(update);

}

//And of course close the connection when you're done:

conn.close();

}
}