How to select values where another value is an array? - php

Question

I'm trying to select values where another POST values are an array, I do not know what is wrong with my query giving me this error. I'm trying to know what courses are just added to table. I have five inputs in the form.
Notice: Trying to get property of non-object in C:\Apache\htdocs\xxx\addcourse.php on line 262
Here is my code
<?php
if(isset($_POST['Submit'])) {
$code= isset($_POST['code']) ? $_POST['code'] : '';
$coursecode = isset($_POST['coursecode']) ? $_POST['coursecode'] : '';
$both=$code[$x] .' '. $coursecode[$x];
$sqlcourses = "SELECT * FROM courses where course_code='$both' ORDER BY course_id DESC LIMIT 5 ";
$resultcourses = $mysqli->query($sqlcourses);
if ($resultcourses->num_rows > 0) {
while($row = $resultcourses->fetch_assoc()) {
?>
</p>
<p> </p>
<p> </p>
<table width="415" border="0">
<tr>
<?php
$courses=$row["course_code"];
echo $courses;
?>
</div>
</tr>
</table>
<?php
}
}
}
?>

Answer 1

First, you build an array of the course codes that you want to retrieve; I'm leaving off the boundary checks for simplicity:
$codes = [];
foreach ($_POST['code'] as $k => $code) {
$codes[] = $code . ' ' . $_POST['coursecode'][$k];
}
Then, you prepare the statement you will use:
$stmt = $mysqli->prepare("SELECT *
FROM courses
WHERE course_code = ?
ORDER BY course_id DESC
LIMIT 5");
Followed by the main loop:
foreach ($codes as $code) {
$stmt->bind_param('s', $code);
assert($stmt->execute());
$res = $stmt->get_result();
while ($row = $res->fetch_assoc()) {
// ...
}
}

Answer 2

you can try this way with small modified code
first you have to convert string to array to get index (x) in array
$code = explode(" ", $code);
$course = explode(" ", $coursecode);
foreach ($code as $cd => $x) {
$both = $code[$x].' '.$coursecode[$x];
$sqlcourses = "SELECT * FROM courses where course_code='$both' ORDER BY course_id DESC LIMIT 5 ";
$resultcourses = $mysqli->query($sqlcourses);
}
second you can choose variable $code or $course as length of loop based on your case
foreach ($course as $crs => $x) {
your condition...
}