Fatal error: Call to a member function fetch() on boolean in {path}

Question

Here is my code:

$money = $db_con
->prepare(" SELECT SUM(asker_amount) asker, SUM(responder_amount) responder
            FROM money WHERE post_id = ? AND author_id = ? AND paid IS NULL")
->execute(array($ques_id, $author_ques_id))
->fetch(PDO::FETCH_ASSOC);
$asker_amount = $money['asker'];
$responder_amount = $money['responder'];

It doesn't execute and throws this error:

Fatal error: Call to a member function fetch() on boolean in {file path} on line 5 (->fetch( ...)

Ok what's wrong? And how can I fix it?

Note: That query works as well, I've tested it in phpmyadmin.

The `execute` function returns a boolean: http://php.net/manual/en/pdostatement.execute.php — Peter Gordon, Jun 16 '16 at 14:23
@pgmann Do you mean I have to fetch `$money` instead of chaining it to `execute()` ? — stack, Jun 16 '16 at 14:24
Obviously it DOESN'T work well here, as some stage of that process is failing and returning a boolean false. In general, never EVER chain DB calls like that. It assume nothing will ever fail, which is exactly the wrong attitude. Queries can fail even if the sql syntax is 100% perfect. **ALWAYS** assume failure, check for failure (at every stage), and treat success as a pleasant surprise. — Marc B, Jun 16 '16 at 14:24
Possible duplicate of [Call to a member function on a non-object](http://stackoverflow.com/questions/54566/call-to-a-member-function-on-a-non-object) — Henders, Jun 16 '16 at 14:39

score 3 · Accepted Answer · edited Jun 16 '16 at 14:50

3

Try this instead.

$query = $db_con->prepare(" SELECT SUM(asker_amount) asker, SUM(responder_amount) responder
        FROM money WHERE post_id = ? AND author_id = ? AND paid IS NULL");
$query->execute(array($ques_id, $author_ques_id));
$money = $query->fetch(PDO::FETCH_ASSOC);
$asker_amount = $money['asker'];
$responder_amount = $money['responder'];

You should be assigning $money the result of the final fetch only.

edited Jun 16 '16 at 14:50

Your Common Sense

156,878
40
214
345

answered Jun 16 '16 at 14:27

Peter Gordon

1,075
1
18
38

`fetch` is a method of `PDOStatement`, not `PDO` – vp_arth Jun 16 '16 at 14:29
@vp_arth Sorry, fixed it! – Peter Gordon Jun 16 '16 at 14:31
and still doesn't check for errors. if the prepare fails and returns boolean false, then over subsequent statement is useless anyways. – Marc B Jun 16 '16 at 14:41
@MarcB May you please write an answer for my question? – stack Jun 16 '16 at 14:41
@MarcB writing error handling code for the every single query is a bit overkill. Especially given that properly configured PHP can report errors by itself. – Your Common Sense Jun 16 '16 at 14:49
I added an example anyway – Peter Gordon Jun 16 '16 at 14:50
@YourCommonSense: true, but if you fail in stage 1, then there's no point in failing in stages 2->n either. – Marc B Jun 16 '16 at 14:50
@YourCommonSense Agreed .. Also that's interesting, usually you are disagree with supper-reputation-users thought. – stack Jun 16 '16 at 14:51
@pgmann would you ever use this kind of code that you added recently? Really? – Your Common Sense Jun 16 '16 at 14:51
@MarcB this is what exceptions exactly are for. – Your Common Sense Jun 16 '16 at 14:52
@YourCommonSense you mean the error checking one? Or my entire answer? I don't follow... – Peter Gordon Jun 16 '16 at 14:56
I mean recent addition you made with extremely laborous error checking code that tripled the amount of code written. To me it's a bit overkill when error handling code is 2 times bigger then the code itself. Don't you think so? – Your Common Sense Jun 16 '16 at 14:57
@YourCommonSense Yeah. As I mentioned, quick but not very streamlined. And pretty redundant due to previously mentioned error logging. You're obviously the expert here (just read your profile!); would you include any error checking at all? – Peter Gordon Jun 16 '16 at 15:00
2

Not in case you only need to report it. Because PDO can report its errors by itself. You have to write a handling code only if you have a certain handling scenario in mind. Otherwise just let PHP report it usual way. – Your Common Sense Jun 16 '16 at 15:03

Fatal error: Call to a member function fetch() on boolean in {path}

1 Answers1