Why is my MySQLi query returning bool(false)?

Question

require_once("LinkDB.php");
$noCommande = $_POST['noCommande'] ;
$req = "Delete From transactions Where no_Commande = ".$noCommande;
require 'config.php';
$connexion = LinkDB::get();

if (!$connexion) 
{

}

if ($connexion)
{   
    $resultat = mysqli_query($connexion,$req) ;
    var_dump($resultat);
    var_dump($req);
}

Integer. I tried to do my query in phpmyadmin, she worked so I don't really understand. Furthermore, the connexion is right because he display my var_dump — thomashoareau, Jun 08 '15 at 10:45
maybe `$noCommande` is undefined. can you check if there is the excpected value? — Jens, Jun 08 '15 at 10:45
My query : `Delete From transactions Where no_Commande = 70214` I tried before to put it in phpmyadmin and it works. — thomashoareau, Jun 08 '15 at 10:47
Also, SQLi warning. use prepared statements to make sure user input is harmless — Hatted Rooster, Jun 08 '15 at 10:48
@HoareauThomas please check for errors after executing the statement. Then you will see if there is an error in your query. — Jens, Jun 08 '15 at 10:48
is there any record in your table which equals to this id 70214?? — habib ul haq, Jun 08 '15 at 10:48
make sure your form is using a POST method and that the element does hold the name attribute for it and with no typos. Error reporting will tell you if there's something wrong. Post your HTML form to be certain. Also make sure your db connection is indeed `mysqli_` and not another API. — Funk Forty Niner, Jun 08 '15 at 10:56
Plus, what's in here `require 'config.php';` ? if that is related to db config, it needs to be before your query, same for `$connexion = LinkDB::get();` — Funk Forty Niner, Jun 08 '15 at 10:57

score 2 · Answer 1 · edited Jun 20 '20 at 09:12

2

As you can see in the documentation:

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.

For DELETEqueries the return false if the query failed.

So that indicates that your query has an error. Call mysqli_error($connexion)); to see the error message.

edited Jun 20 '20 at 09:12

Community

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answered Jun 08 '15 at 10:49

Jens

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I know but I got false, I should get true – thomashoareau Jun 08 '15 at 10:52
is there any record in your table which equals to this id 70214?? – habib ul haq Jun 08 '15 at 10:53
1

@habibulhaq I do not think that delete will return false if there is no record with this id. – Jens Jun 08 '15 at 10:55
Yes. I tried this @Jens : Warning: mysqli_error() expects parameter 1 to be mysqli, boolean given – thomashoareau Jun 08 '15 at 10:56
@HoareauThomas sorry. try my updated anser. Have changed `$reg` by `$connexion` – Jens Jun 08 '15 at 10:58
like before boolean and not mysqli – thomashoareau Jun 08 '15 at 10:59
@HoareauThomas have you echod the result of `mysqli_error($connexion);`? – Jens Jun 08 '15 at 11:01
1

Yes. I got this `Warning: mysqli_error() expects parameter 1 to be mysqli, null given` – thomashoareau Jun 08 '15 at 11:13
@HoareauThomas Then it looks like your connection is not established. Can you check it please. – Jens Jun 08 '15 at 11:14
In fact, I got a acces denied to my bdd. I'm on it – thomashoareau Jun 08 '15 at 11:18
1

I settled my problem, the file config.php got a bad server name. – thomashoareau Jun 08 '15 at 11:23

score 0 · Answer 2 · answered Jun 08 '15 at 10:44

0

$noCommande is string, it came from form. You forgot quotes around it.

$req = "Delete From transactions Where no_Commande = '" . $noCommande . "'";

Or, if you send a number in form, you can change variable type.

$req = "Delete From transactions Where no_Commande = " . (int)$noCommande;

answered Jun 08 '15 at 10:44

pavel

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`$req = "Delete From transactions Where no_Commande = ".(int)$noCommande;` I do that and it's the same result – thomashoareau Jun 08 '15 at 10:50
@HoareauThomas: and `print_r ($noCommnade)` returns? – pavel Jun 08 '15 at 10:51

Why is my MySQLi query returning bool(false)?

2 Answers2