How to save date only once per day in the table - php

Question

I have a login form who data are stored in a table users. I also have another table that stores the login date and time.
The table users (id, username, password)
The table user_login (id, user_id, login_date)
The code I tried:
$db = mysqli_connect('localhost', 'root', '', 'registration');
if (count($errors) == 0) {
$password = md5($password);
$query = "SELECT * FROM users WHERE username='$username' AND password='$password'";
$results = mysqli_query($db, $query);
if (mysqli_num_rows($results) == 1) {
$_SESSION['username'] = $username;
$name = $_SESSION['username'];
$row=mysqli_fetch_array($results);
$user_id= $row['id'];
$date = date('Y-m-d');
$checkdate= "SELECT id from user_login WHERE user_id='$user_id' AND DATE(login_date)='$date'";
$check=mysqli_query($db, $checkdate)or die(mysqli_error($db));
if(mysqli_num_rows($check)==1){
$updatedate="UPDATE user_login set date= $date where id=$user_id";
mysqli_query($db,$updatedate)or die(mysqli_error($db));
}
else{
$insertdate="INSERT INTO user_login (user_id, login_date) values($user_id, $date)";
mysqli_query($db,$insertdate)or die(mysqli_error($db));
}
// $_SESSION['success'] = "You are now logged in";
header('location: profile.php');
}else {
array_push($errors, "Wrong username/password combination");
}
}
}
The above code just adds date and time every time I login. But I want to save the date only once per day.

Answer 1

Here's one idea.
You could save date into your user_login table and then you can check and compare it
Before inserting into your user login table you would then check it.
Get id of the user from $results.
And check table:
$date=date('Y-m-d');
Select id from user_login where user_id = $user_id and Date(login_date) = $date
If there is a record just update date
$cur_date=date('Y-m-d');
Update user_login set date=$cur_date where id=$user_login_id
else insert one
INSERT INTO user_login (user_id, login_date) values($user_id, $cur_date);
I hope you understand the logic.
I hope you are using mysqli_escape_string in order to prevent from sql injection.
Don't use md5 for password encryption use bcrypt or other secure encryption functions.
here is working version of your code. Don't use it in production.
$db = mysqli_connect('localhost', 'root', '', 'registration');
if (count($errors) == 0) {
$password = md5($password);
$query = "SELECT * FROM users WHERE username='$username' AND password='$password'";
$results = mysqli_query($db, $query);
if (mysqli_num_rows($results) == 1) {
$_SESSION['username'] = $username;
$name = $_SESSION['username'];
$row = mysqli_fetch_array($results);
$user_id = $row['id'];
$date = date('Y-m-d');
$datetime = date('Y-m-d H:i:s');
$checkdate = "SELECT id from user_login WHERE user_id='$user_id' AND DATE(login_date)='$date'";
$check = mysqli_query($db, $checkdate) or die(mysqli_error($db));
if (mysqli_num_rows($check) == 1) {
$updatedate = "UPDATE user_login set login_date='$datetime' where user_id=$user_id and DATE(login_date)='$date'" ;
mysqli_query($db, $updatedate) or die(mysqli_error($db));
} else {
$insertdate = "INSERT INTO user_login (user_id, login_date) values($user_id, '$datetime')";
mysqli_query($db, $insertdate) or die(mysqli_error($db));
}
// $_SESSION['success'] = "You are now logged in";
header('location: profile.php');
die;
}else {
array_push($errors, "Wrong username/password combination");
}
}
this is just demonstration.