KDB/Q: Why I got length error when select data using vector condition for symbol list?
<p>I have a table:</p>

<pre><code>t3:([]a:2 3 4;b:`CA`AB`)
</code></pre>

<p>I have a query:</p>

<pre><code>select from t3 where b in ?[a=2;`CA`AB;`AB]
</code></pre>

<p>Bong... it give me `length error.</p>

<p>But these works:</p>

<pre><code>select from t3 where b in ?[a=2;`CA;`AB] 

select from t3 where b in `CA`AB
</code></pre>

<p>Cannot think of where goes wrong? Please help... Thanks.</p>