Call to a member function bind_param() on a non-object (unable to solve despite research)
<pre><code>$stmt = $mysqli-&gt;prepare('select Un from member where Lock = ? and Activated = ?');
$stmt -&gt; bind_param("ss", 'N', 'Y');//This line gave the error
$stmt -&gt; execute();
$stmt-&gt;store_result();//apply to prepare statement
$numRows = $stmt-&gt;num_rows;

if ($numRows &gt; 0)//if have result
 while ($row = $stmt-&gt;fetch())
</code></pre>

<p>my above code gave me a <strong>"Call to a member function bind_param() on a non-object"</strong> error.
I really don't get it why i getting this error. I have correct cols name.</p>

<p>I am new to mysqli and would like to learn how to debug such error.</p>

<ol>
<li>what is the problem with my prepare statement or bind_param()?</li>
<li>Please teach me how to debug such error</li>
</ol>
