To understand a line of PHP
<p><strong>What does the following line mean, particularly the operator <code>.=</code> ?</strong></p>

<pre><code>$query .= "UPDATE authors SET author=LOWER(author) WHERE id=2;";
</code></pre>

<p>in <a href="http://us2.php.net/manual/en/function.pg-query.php" rel="nofollow">the code</a></p>

<pre><code>&lt;?php

$conn = pg_pconnect("dbname=publisher");

// these statements will be executed as one transaction

$query = "UPDATE authors SET author=UPPER(author) WHERE id=1;";
$query .= "UPDATE authors SET author=LOWER(author) WHERE id=2;";

pg_query($conn, $query);

?&gt;
</code></pre>

<p>It seems to make some sort of array such that the last command processes first the first query and then the second.</p>
