PHP - How To Store Value From A Array Into One Variable?

Currently I am adding the concept of "entitlements" to my website.

In the past, my "article.php" script would simply look to the URL for which article was being requested and then load it.  However now that I am also adding the concept of "premium content" for "paid members", I need a way to control who sees what.

What I am wondering is - from a security standpoint - how much information I should load into the $_SESSION variable.

For instance, right now when a user logs in, I think I just store the "memberID" and "FirstName" and possibly "Username".

It would be more efficient when a Member logs in to also retrieve their "Membership Plan" and store that in the $_SESSION variable, so that as they browse my website, each page can simply grab $_SESSION['MembershipPlan'] and run that through a function that I need to build and then determine if the user gets to access said page.

However, maybe it would be more secure to have it so when a user lands on page XYZ, I would look at their "memberID" and query the database to get their "MembershipPlan"?

Any thoughts on each approach?

Again, my main concern is *security*, but I also suppose this plays into "performance".

    //multi query
    $sql= "SELECT option_value FROM settings WHERE option_name = 'email_temp_issue';";  //1
    $sql .="SELECT title FROM books WHERE id = '$bookid';";  //2
    $sql .="SELECT fullName from students WHERE email = '$username'";  //3
    $sql_run = mysqli_multi_query($connection,$sql);
    if(mysqli_num_rows($sql_run)>0)
    {
        foreach ($sql_run as $row)
        {
            $email_template = $row['option_value']; //retrieve from query 1
            $title = $row['title']; //retrieve from query 2
            $name = $row['fullName']; //retrieve from query 3
        }
    }

I am trying to store the data from the multi query into each variable, which I am not sure how to do..Anyone can help? :)

Hello,

I'm trying to store the match I get in $result to a variable so that I can easily compare its other values against other values. Here is my code..

//loop through new orders array
foreach ( $orders as $order ) {
	
	//compare job number and line item against database information for a match
	if ( array_search ( $order[ 'job_number' ], array_column ( $result, 'job_number' ) ) !== false && array_search ( $order[ 'line_item' ], array_column ( $result, 'line_item' ) ) !== false ) {
		
		$db_match = key($result);
		
		echo '<br><br>'.$db_match.'<br><br>';
		
		echo 'Job: ' . $order['job_number'] . '/Line Item: ' . $order['line_item'] . ' was found<br>';
	
	//new order which doesn't exist in database
	} else {
		echo 'Job: ' . $order['job_number'] . '/Line Item: ' . $order['line_item'] . ' was not found<br>';
	}
}

When I do $db_match = key($result); I get 0 each time and when I do: 

$db_match = array_search ( $order[ 'job_number' ], array_column ( $result, 'job_number' ) ) !== false && array_search ( $order[ 'line_item' ], array_column ( $result, 'line_item' ) ) !== false;

I get 1 each time...which I assume is the number of matches which meet that criteria instead of the array key I found a match on.

{'data_1': 'data_2', 'data_3': 'data_4', 'data_5': 'data_6', 'data_7': 'data_8'}

<form method="post" action="<?php echo $_SERVER['PHP_SELF'] ?>">
    <input type="text" name="hashtags" />
    <input type="submit" name="submit" />

</form>
<?php

include("connect.php");

?>
<?php

if(isset($_POST['submit'])){

    $hashtags = explode(", ", $_POST['hashtags']);

    for($i= 0; $i < count($hashtags); $i++){

        $tqs = "SELECT `id` FROM `hashtags_two` WHERE `hashtags` = '" . $hashtags[$i] . "'";
        $tqr = mysqli_query($dbc, $tqs) or die(mysqli_error($dbc));

    }

    $fetch_array = array();
    while($row = mysqli_fetch_array($tqr)){
        $fetch_array[] = $row['id'];
    }

}

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