[RESOLVED] prepare() function problem

[condoug]

Hi

I am dipping my toe in the water of prepared statements, and my function below is not working, i am getting nothing returned where I expect to see some content in my page:

function getPageText($url) {
    global $dblink;
    $qry = "SELECT content FROM tblsections WHERE url = ?";

if ($stmt = $dblink->prepare($qry)) {
    $stmt->bind_param("s",$url);
    $stmt->execute();
    $stmt->bind_result($content);
    $stmt->close();
    return str_replace("/documents/editorfiles/","/repository/documents/editorfiles/",$content);
}
} 

I am not sure how to debug prepared statments, normallly with a mysqli_query() I would just put a die statement on the end which would tell me the problem.

Thank you for any advice in advance.

[bradgrafelman]

condoug;11029649 wrote:

normallly with a mysqli_query() I would just put a die statement on the end which would tell me the problem.

Why wouldn't you presume the same should hold true for the OOP methods as well as prepared statements? Looking in the PHP manual, you'll find that all four methods you're calling inside the if() statement return a boolean indicating whether the command was successful.

Thus, you might want to consider checking to see if each of those commands did in fact execute successfully. Next, have you verified that error_reporting is set to E_ALL (or better) and either display_errors or log_errors is set to On?

[condoug]

Hi bradgrafelman

OK, I have updated my script (below) and I know the query is being prepared however it returns NULL. When I run the query directly on the server, i get the expected result.

Can you spot anything wrong with the query? (I have hard coded the query WHERE clause to keep things even simpler)

function getPageText($url) {
    global $dblink;
    $qry = "SELECT content FROM tblsections WHERE url = 'about'"; // hard coded query

if ($stmt = $dblink->prepare($qry)) {
    //$stmt->bind_param("s",$url);
    $stmt->execute();
    $stmt->bind_result($content);
    var_dump($content); // this shows me NULL
    $stmt->close();
    return str_replace("/documents/editorfiles/","/repository/documents/editorfiles/",$content);
} else {
    error_log("Prepare failed:".PHP_EOL.$dblink->error.PHP_EOL.$qry,1,"[e-mail]");
    return false;
}  

Any thoughts?

[condoug]

Found and fixed the problem. I had to put a while() loop in in order to fetch() the data. Doesn't see right to me using a while() loop when I know there is only ever one resuly but at least it works...

					if ($stmt = $dblink->prepare($query)) {
						//$stmt->bind_param("s",$url);
						$stmt->execute();
						$stmt->bind_result($content);
						while ($stmt->fetch()) {
							echo $content;
						}
						$stmt->close();
					}

[bradgrafelman]

You don't need the while loop, but you do need to fetch() the results once (something your previous code snippet didn't do at all).