在mysqli提取循环中无法调用函数

Question

This code just does not work.

$queryProduct = $mysqli->prepare("SELECT productID FROM products WHERE productCat=?");
$queryProduct->bind_param('i', $id);
$queryProduct->execute();
$queryProduct->bind_result($productID);
while ($queryProduct->fetch()) 
{
smallBlockProduct($productID);
}
$queryProduct->close();

This gives me the error "Fatal error: Call to a member function fetch_assoc() on a non-object in" on the line that calls smallBlockProduct.

How ever, if i change the function smallBlockProduct to a simple echo $productID; it will loop through all the correct results.

Can I not call a function in a mysqli fetch loop? Or is there a special way to call a function?

EDIT:

The error is actually on the function I am calling. The function exectues another query.

function smallBlockProduct($productID)
   {    
    global $mysqli;

    $query = "SELECT productName FROM products WHERE productID='$productID'";
    $result = $mysqli->query($query);
    while ($row = $result->fetch_assoc())
        {
        $productName = $row['productName'];
        echo $productName.'<br>';
        }
    }

So now, can I not perform a different query while already in another query?

Answer 1

It looks like you're trying to call ->fetch_assoc() on $productID that you're passing in to the smallBlockProduct() function.

I'd suggest checking what $productID is in the function..

function smallBlockProduct($productID){
    var_dump($productID);
...

Answer 2

In response to this: So now, can I not perform a different query while already in another query?

You cannot use the same Database connection to execute a second query without losing the first. To run a second query you would need to open another connection.