Using PHP how do I retrieve a certain field value from a database table and then input that single field value into a new table

Question

This is something I've tried... I'm using a select statement to get the id from the parent table where the email is equal to the email provided by the user. After getting the id from the parent table I want to set this id to the parent_id field in the child table to a field value in a child table.

For instance, my parent table has id, first_name, last_name, address, phone, email, picture_approval and date. Then the child table has id, child_first_name, child_last_name, and parent_id

// already connected to database successfully
   {
        try
        {
            $sql = 'INSERT INTO parents SET
            first_name = :fname,
            last_name = :lname,
            address = :address,
            phone = :phone,
            email = :email,
            picture_approval = :picture,
            date = NOW()';

            $s = $pdo->prepare($sql);
            $s->bindValue(':fname', $_POST['g_first_name']);
            $s->bindValue(':lname', $_POST['g_last_name']);
            $s->bindValue(':address', $_POST['address']);
            $s->bindValue(':phone', $_POST['phone']);
            $s->bindValue(':email', $_POST['email']);
            $s->bindValue(':picture', $_POST['pictures']);
            $s->execute();
        }
        catch (PDOException $e)
        {
            $errors[] = 'Error adding parent to database.';
        }
    }
//the above code works perfectly

But then this next part never works.

try 
   {
        $sql = "SELECT id FROM parents WHERE email = :email";
        $s = $pdo->prepare($sql);
        $s->bindValue(':email', $_POST['email']);
        $s->execute();
        $s->bind_result($returned_id);

        $s->fetch();

        $fieldValue = "$returned_id";


   }
   catch (PDOException $e)
    {
        $errors[] = 'Error retrieving parent.';
    }

Then I want to set up my INSERT INTO child statement... but not really sure how since my SELECT statement does not appear to be working right. I did find this PHP function to extract a field value from a database but it only outputs the value, I need it to put it into another table.

Answer 1

$fieldValue = $returned_id;

$returned_id shouldn't be in quotes