composer does not install mongodb ubuntu
<p>I ran: <code>composer require mongodb/mongodb</code>. But it gave me the following error : </p>

<p>has error:</p>

<blockquote>
<pre><code>- mongodb/mongodb 1.0.1 requires ext-mongodb ^1.1.0 -&gt; the requested PHP extension mongodb is missing from your system.
- mongodb/mongodb 1.0.0 requires ext-mongodb ^1.1.0 -&gt; the requested PHP extension mongodb is missing from your system.
- Installation request for mongodb/mongodb ^1.0 -&gt; satisfiable by mongodb/mongodb[1.0.0, 1.0.1].
</code></pre>
</blockquote>

<p>I tried : <code>composer show -p</code></p>

<p>Then it gave me:</p>

<pre><code>......
ext-iconv           0         The iconv PHP extension
ext-mcrypt          0         The mcrypt PHP extension
ext-mhash           0         The mhash PHP extension
ext-mongo           1.6.12    The mongo PHP extension
ext-mysql           1.0       The mysql PHP extension
ext-mysqli          0.1       The mysqli PHP extension
......
</code></pre>

<p>Why am I getting the error?</p>

<p><code>php -m</code></p>

<pre><code>..... 
libxml 
mbstring 
mcrypt 
mhash 
mongo 
mysql 
mysqli 
openssl 
pcntl
pcre
 PDO 
 .....
</code></pre>

<p>I'm using ubuntu 14.04 LTS</p>