how can I insert data into table php/mysql? [duplicate] - php

Question

This question already has answers here:
How to include a PHP variable inside a MySQL statement
(5 answers)
Closed 3 years ago.
I'm making a quiz and once the calculation of the grade is finished, I want to add that data to test_attempt table.
Here's its structure.
Here's the code of the query:
<?php
$connection = mysqli_connect("localhost", "root", "", "vartvald");
if ($connection->connect_error) {
die("Connection failed:" . $connection->connect_error);
}
$user=$_SESSION['user'];
$userid=$_SESSION['userid'];
$sql = "INSERT INTO test_attempts (date, id, mark, top_mark, fk_user, fk_test) VALUES
('',null,'$grade','$top_grade','$userid','$fk');";
var_dump($sql);
$connection->close();
?>
What am I doing wrong?

Answer 1

You have few mistakes. Your main problem is that you never prepared any query and never executed it. To do it you need to use prepare(), bind_param(), and execute(). Also you are not opening the mysqli connection correctly and your error checking will never work (Please read: Should we ever check for mysqli_connect() errors manually?)
After fixing your errors your code would look something like this:
<?php
mysqli_report(MYSQLI_REPORT_ERROR | MYSQLI_REPORT_STRICT);
$connection = new mysqli("localhost", "root", "", "vartvald");
$connection->set_charset('utf8mb4');
$user = $_SESSION['user'];
$userid = $_SESSION['userid'];
$stmt = $connection->prepare('INSERT INTO test_attempts (date, id, mark, top_mark, fk_user, fk_test) VALUES(NULL,NULL,?,?,?,?)');
$stmt->bind_param('ssss', $grade, $top_grade, $userid, $fk);
$stmt->execute();
I have not validated whether your SQL is correct in itself, but if you have error reporting switched on, PHP should tell you if you have a mistake.

Answer 2

Your code will never add data in the database because you aren't calling any funciton that insert data:
$sql = "INSERT INTO test_attempts (date, id, mark, top_mark, fk_user, fk_test) VALUES
('',null,'$grade','$top_grade','$userid','$fk');";
var_dump($sql);
// missed code to insert data in the database
$connection->close(); // here you close the connection
Before closing the connection, call mysqli_query:
mysqli_query($connection,"$sql");

Answer 3

Try this:
$sql = "INSERT INTO test_attempts (date, id, mark, top_mark, fk_user, fk_test) VALUES
(CURRENT_TIMESTAMP,null,'$grade','$top_grade','$userid','$fk');";

Answer 4

Try the following, here you can see that the CURRENT_TIMESTAMP is passed as first params for data and also below the $sql you can see the mysqli_query which is useed here to execute the insert query.
$sql = "INSERT INTO test_attempts (date, id, mark, top_mark, fk_user, fk_test) VALUES
(CURRENT_TIMESTAMP,null,'$grade','$top_grade','$userid','$fk');";
mysqli_query($connection, $sql);