Sql returns empty row on combinning primary key with another value in where clause
<p>I am getting empty row on following sql</p>

<pre><code>SELECT * FROM flyers WHERE fId='6' AND 'userId'='400' 
</code></pre>

<p>MySQL returned an empty result set </p>

<pre><code>(i.e. zero rows). (Query took 0.0004 sec)
</code></pre>

<p>But when i use </p>

<pre><code>SELECT * FROM flyers WHERE fId='6'
</code></pre>

<p>Showing rows </p>

<pre><code>0 - 0 (1 total, Query took 0.0005 sec).
</code></pre>

<p>As i got my result and that is correct using only primary key.</p>

<p>But i does not know why mysql returns empty row on using AND with primary key.</p>

<p>Note:- fId is flyer table primary key.</p>