Concatenate in PostgreSQL
<p>I have a table with width and height (both integers). I want to display it as are.
For eg: width = 300 and height = 160.
Area = 300 x 160.
I am using the following query </p>

<pre><code>  select cast(concat(width,'x',height) as varchar(20)) from table;
</code></pre>

<p>or </p>

<pre><code>select concat(width,'x',height) from table;
</code></pre>

<p>but I am getting the following error.</p>

<pre><code>ERROR: function concat(character varying, "unknown", character varying) does not exist

Hint: No function matches the given name and argument types. You may need to add explicit type casts.
</code></pre>

<p>Can anyone tell me how to do this?
Thanks</p>