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POHow can I convert the result of this postgres db query into json to return to my jquery call?
 

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  1. POHow can I convert the result of this postgres db query into json to return to my jquery call?
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    <p>I'm creating a contest sign-up page for our annual math competition at my school. It requires some AJAX like behavior when you click and select an item in a dropdown list.</p> <p>I've gotten an event to fire when I select something in the dropdown (I'm currently showing an alert box):</p> <pre><code>&lt;script type="text/javascript"&gt; $(function() { $("#student").change(onStudentChange); }); function onStudentChange() { alert("Dropdown changed"); } &lt;/script&gt; </code></pre> <p>What this needs to do, is do an asynchronous call to the server to get a list of contests that student is currently registered for.</p> <p>I know I need to do a jquery ajax call. So I think my onStudentChange() function would look like this:</p> <pre><code>$.ajax({ type : 'POST', url : 'get_registered_events.php', dataType : 'json', data: { studentid : $('#student').val() }, success : function(data){ // Do something once we get the data }, error : function(XMLHttpRequest, textStatus, errorThrown) { // Display error } }); return false; }); </code></pre> <p>So I went ahead and created the <code>get_registered_events.php</code>, which I want to return the events the student is registered for. </p> <p>My problem is, I'm not experienced with PHP and I'm having difficulty figuring out how I would return the data the database gave me to this ajax call in the JSON format. Another snag I have is our school is using a very old version of PHP so I have to use this <a href="http://www.extjs.com/learn/Tutorial:Creating_JSON_Data_in_PHP#Less_than_PHP_5.2.0_and_no_root_access_.28.2ANIX.29" rel="nofollow noreferrer">PEAR JSON</a> library.</p> <p>Here is that PHP file I'm having trouble with:</p> <pre><code>&lt;?php if (!empty($_POST['studentid')) { include_once('JSON.php'); $json = new Services_JSON(); $dbconn = pg_connect("host=somehost dbname=somedb user=someuser password=somepassword") or die('Could not connect: ' . pg_last_error()); $query = 'SELECT contest.id, contest.title, FROM contest, student_contest WHERE student_id = '.$_POST['studentid'].' AND contest.id = contest_id'; $contests = pg_query($query) or die('Query failed: ' . pg_last_error()); // Here I need to convert the rows of $contests (contest.id, contest.title), into JSON and return it to that ajax call. } ?&gt; </code></pre> <p>So my question is, how do I convert $contests (its rows), into JSON (contest.id, contest.title), and return that back to the ajax call that will make it above.</p> <p>If anyone could point me in the right direction I would really appreciate it.</p>
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    1. COYou have a SQL injection vulnerability; ask your teacher to warn against them.
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    2. COCan you get your school to upgrade to a newer version of PHP?
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    3. CO@SLaks, the bureaucracy surrounding our Universities IT department is stifling. It definitely wont happen in time for the competition.
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