The type 'DbConnection' is defined in an assembly that is not referenced. I cannot add the reference?
<p>In Visual Studio (same issue in 2013 &amp; 2015 Editions), I am getting this error when building my project:</p>

<pre><code>The type 'DbConnection' is defined in an assembly that is not referenced. You must add a reference to assembly 'System.Data, Version=4.0.0.0
</code></pre>

<p>I am doing this as I would like to use the <code>MySQL.Data</code> package, but it seems to require <code>System.Data</code>. </p>

<p>However, in my project there is no way to add <code>System.Data</code> to my references, it is not in the list of references so I cannot 'tick' it to add it to the project. This is a <code>Xamarin C#</code> solution, and the project that does not list <code>System.Data</code> is a PCL. </p>

<p>Does this affect the packages? If so, is there some way to work around this or get MySQL.Data working without this?</p>