Warning: mysqli_free_result() again

Question

I get this error:

Warning: mysqli_free_result() expects parameter 1 to be mysqli_result, boolean given in

In my code, I have:

// Perform it
$result = mysqli_query($connection, $query);

if ($result) {
  // Success
  echo "<h1>Uploaded results to database</h1>";
} else {
  echo "FAILURE: Couldn't perform query on database: " . mysqli_error($connection);
}


// Release
mysqli_free_result($result);

Most other solutions I have read say it is because the query might have failed, but that is not the case, because I test the returned data from the query to see if it exists, and it does, so the <h1> tag gets executed. How come I can't release it then? I thought I should always released returned data when I was done working with it?

From the manual: "Returns **FALSE** on failure. For successful `SELECT`, `SHOW`, `DESCRIBE` or `EXPLAIN` queries `mysqli_query()` will return a `mysqli_result` object. For **other successful queries** `mysqli_query()` will return **TRUE**" - my guess is that you're using an `UPDATE` query - and therefore you get a **TRUE** (boolean) return. You can only use `mysqli_free_result` on those queries which return a `mysqli_result` object — naththedeveloper, Nov 08 '13 at 11:20
Does this answer your question? [mysqli\_fetch\_assoc() expects parameter / Call to a member function bind\_param() errors. How to get the actual mysql error and fix it?](https://stackoverflow.com/questions/22662488/mysqli-fetch-assoc-expects-parameter-call-to-a-member-function-bind-param) — Dharman, Mar 16 '20 at 00:25

score 3 · Accepted Answer · answered Nov 08 '13 at 11:26

You should have a look at the manual.

Returns FALSE on failure. For successful SELECT, SHOW, DESCRIBE or EXPLAIN queries mysqli_query() will return a mysqli_result object. For other successful queries mysqli_query() will return TRUE"

My guess is that you're using an UPDATE query - and therefore you get a TRUE (boolean) return. You can only use mysqli_free_result on those queries which return a mysqli_result object.

To re-iterate, if you use a SELECT, SHOW, DESCRIBE or EXPLAIN query and the query runs successfully, you can make use of mysqli_free_result.

If you use anything other than the 4 mentioned above (like INSERT or UPDATE) you can't make use of mysqli_free_result because the result will always be TRUE (if successful) or FALSE (if failed).

I found this seems to allow the best of both worlds… `if (gettype($result)==="object") mysqli_free_result($result);` — JoLoCo, Oct 23 '14 at 00:15

Bhavik Shah · Answer 2 · 2013-11-08T11:25:36.283

0

This happens when error is generated while executing query.
So, $result will have boolean value false.
You should try to release inside if clause

For more details, you can refer "Procedural style" example at official documentation

edited Nov 08 '13 at 11:25

answered Nov 08 '13 at 11:19

Bhavik Shah

2,250
1
16
32

score 0 · Answer 3 · answered Jan 07 '15 at 13:28

0

Use This: $result->close();

answered Jan 07 '15 at 13:28

Ferhat KOÇER

3,394
23
25

Answers should should consist more than just plain code. The author of the question states clearly that he has problems in understanding the issue he describes. – hugo der hungrige Jan 07 '15 at 14:09

Warning: mysqli_free_result() again

3 Answers3