MYSQLi - Filtering results

[merkont]

Hey,

 

Wrote I quick script to filter results from database.

It kinda works but not sure if this is best or even secure way to do it.

I know mysqli has function 'bind_params', but failed to make it work.

<form action="" method="get">
<input type="checkbox" name="data" value="3" />
<input type="submit" />

<?php
if( empty($_GET['data']) ) {
die("GET empty"); }

$mysqli = new mysqli('localhost', 'user', 'password', 'database');
$statement = "SELECT * FROM table1 WHERE id=" . $_GET['data'];

$result = $mysqli->query($statement);
while( $row = $result->fetch_assoc() ) {
        echo $row['id'];
        echo "<br/>";
        echo $row['text'];
        if ($row['img'] !=  NULL)
        echo "<img src=" . $row['img'] . " > ";
}

?>

So just basic checkbox interface, when selected one of checkboxes and submitted, script queries database with matching ID from GET, returns results and loops through them.

Inside loop checks for associated image src, if not present ignores field.

 

I want to use this fucntions logic in my project but not sure if secure nor best/easiest way to do this.

Obviously will improve interface, naming of variables etc.

[Psycho]

EDIT:

 

NEVER put user entered data into a query (unless you are using prepared statements). In this case you can use intval() on the value

$id = intval($_GET['data']);
$statement = "SELECT * FROM table1 WHERE id={$id}";

As to your issue, MySQL does not return NULL for a NULL field. Just check if the value is not empty. Plus, there are no quotes around the value

 

 

if (!empty($row['img']))
{
    echo "<img src=\"{$row['img']}\">";
}

Edited March 31, 2014 by Psycho

[DavidAM]

While I agree that the test should be if (!empty($row['img'])); the manual says:

 

Note: This function sets NULL fields to the PHP NULL value.

for both mysql and mysqli

 

http://php.net/manual/en/function.mysql-fetch-assoc.php

 

http://php.net/manual/en/mysqli-result.fetch-assoc.php

[jazzman1]

 

unless you are using prepared statements

You should get an error message if you try to use superglobals along with prepared queries

[Psycho]

While I agree that the test should be if (!empty($row['img'])); the manual says:

 

 

for both mysql and mysqli

 

http://php.net/manual/en/function.mysql-fetch-assoc.php

 

http://php.net/manual/en/mysqli-result.fetch-assoc.php

 

I stand corrected. I could have sworn it did not do that.