PHP mysqli can't fetch data

Question

Hy,

I have a strange problem. This is the code:

First, I get the parameters and connect to the base.

<?php
    include('connect.php');
    $id=$_GET['id']; // if I echo this, it outputs 0
    $category=$_GET['category'];// if I echo this, it outputs 'category1'
    $name=$_GET['name'];
 ?>

And now I went to fetch the data from the db:

<?php
    if ($stmt = $mysqli->prepare("SELECT modelID,modelName,modelLogo FROM model,maker WHERE model.makerID=maker.makerID AND model.makerID='.$id.' AND model.modelCategory='.$category.' ORDER BY modelName")) { 

    $stmt->execute();

    $stmt->bind_result($modelID, $modelName,$modelLogo);

    while ($stmt->fetch()) {
        echo '<a href="edit_model.php?id='.$modelID.'"><div class="box"><img src="'.$modelLogo.'" /><p>'.$modelName.'</p></div></a>';
    }

    $stmt->close();

    }

    else {
        printf("Prepared Statement Error: %s\n", $mysqli->error);
     }
?>

And this won't output nothing. But when i run the sql query in myPhpAdmin, it returns the values.

Query:

SELECT modelID,modelName,modelLogo 
FROM model,maker 
WHERE model.makerID=maker.makerID 
AND model.makerID='0' 
AND model.modelCategory='category1' 
ORDER BY modelName

Output: 0 // name // path

I put error_reporting(E_ALL); but it doesn't return any error. Also, I tried to put this code after the $stmt->bind_result($modelID, $modelName,$modelLogo); and this is the result:

var_dumb($modelID);die(); it returned '0'.

var_dumb($modelName);die(); it returned 'NULL'.

var_dumb($modelLogo);die(); it returned 'NULL'

I can't figure out what's going on so any help is needed.

Answer 1

It's because your query in the PHP is bogus, change this:

... AND model.modelCategory='.$category.' ...

To this:

... AND model.modelCategory='$category' ...

Or better yet, since you are already using prepared statements, use parameter binding so you don't have to worry about this kind of thing.

Answer 2

You are not binding the parameters. Try this.

if ($stmt = $mysqli->prepare("SELECT modelID,modelName,modelLogo FROM model,maker 
    WHERE model.makerID=maker.makerID 
    AND model.makerID = ? AND model.modelCategory = ? 
    ORDER BY modelName")) {
$stmt->bind_param('ss', $id, $category);
//rest of the code intact

Answer 3

Sean Bright answered your question, but I'd prefer this one:

"SELECT 
  modelID, modelName, modelLogo 
FROM 
  model, maker 
WHERE 
  model.makerID=maker.makerID AND model.makerID='{$id}' 
AND 
  model.modelCategory='{$category}' 
ORDER BY modelName"

Just because such code editors as Notepad++ hightlight variables in strings making it easy to read.