Fatal error: Uncaught Error: Call to a member function fetch() on array

hder :

When I execute the following code, the output is fine, I get 3 records:

$sql = "SELECT * FROM log WHERE follow=1 AND action = 'new' AND processed = 0 AND type = 'question'";
$result = $db->prepare($sql);
$result->execute();
while($row = $result->fetch(PDO::FETCH_ASSOC)):
    echo $row['action']." ".$row['type']." id: ".$row['type_id'].'<br>';
    //insert more sql in here
endwhile;

NO ERRORS.

I have more sql that I test separately before I add into the while loop:

    $id=$row['type_id'];
    //retrieve all new questions - name and content & compile into message
    $stmt = $db->prepare("SELECT * FROM questions WHERE question_id=?");
    $stmt->execute([$id]); 
    $result = $stmt->fetch();
    $content = $result['question'];
    $author_id = $result['user_id'];

    //get author name
    $stmt = $db->prepare("SELECT username FROM users WHERE id=?");
    $stmt->execute([$author_id]); 
    $result = $stmt->fetch();
    $name = $result['username'];
    echo '<strong>'.$name.': </strong>'.$content.'<br>';

I use a number for $id for testing and I get results.

NO ERRORS.

When I insert this code in to the while loop, I get the fatal error. It executes one loop and fails.

Fatal error: Uncaught Error: Call to a member function fetch() on array

The complete code:

$sql = "SELECT * FROM log WHERE follow=1 AND action = 'new' AND processed = 0 AND type = 'question'";
$result = $db->prepare($sql);
$result->execute();
while($row = $result->fetch(PDO::FETCH_ASSOC)):
    //echo $row['action']." ".$row['type']." id: ".$row['type_id'].'<br>';
    $id=$row['type_id'];
    //retrieve all new questions - name and content & compile into message
    $stmt = $db->prepare("SELECT * FROM questions WHERE question_id=?");
    $stmt->execute([$id]); 
    $result = $stmt->fetch();
    $content = $result['question'];
    $author_id = $result['user_id'];

    //get author name
    $stmt = $db->prepare("SELECT username FROM users WHERE id=?");
    $stmt->execute([$author_id]); 
    $result = $stmt->fetch();
    $name = $result['username'];
    echo '<strong>'.$name.': </strong>'.$content.'<br>';

endwhile;

I suspect something very simple, but can't seem to see it. Thanks in advance!

hder :

Became so obvious after taking a little lunch break - I was using $result for all 3 queries. I changed it to $result, $result2, $result3 and that solved the problem:

$sql = "SELECT * FROM log WHERE follow=1 AND action = 'new' AND processed = 0 AND type = 'question'";
$result = $db->prepare($sql);
$result->execute();
while($row = $result->fetch(PDO::FETCH_ASSOC)):
    //echo $row['action']." ".$row['type']." id: ".$row['type_id'].'<br>';
    $id=$row['type_id'];
    //retrieve all new questions - name and content & compile into message
    $stmt = $db->prepare("SELECT * FROM questions WHERE question_id=?");
    $stmt->execute([$id]); 
    $result2 = $stmt->fetch();
    $content = $result2['question'];
    $author_id = $result2['user_id'];

    //get author name
    $stmt = $db->prepare("SELECT username FROM users WHERE id=?");
    $stmt->execute([$author_id]); 
    $result3 = $stmt->fetch();
    $name = $result3['username'];
    echo '<strong>'.$name.': </strong>'.$content.'<br>';
endwhile;