Azure DocumentDB vs Blob Storage for multiple PDF files per user
<p>I am developing my first application as a learning project doing absolutely everything:</p>

<ul>
<li>Client frontend (angular)</li>
<li>Backend (OWIN Self Host, ASP.NET Web Api 2)</li>
<li>Database and hosting (Azure deployment)</li>
</ul>

<p>Its been a learning process so far and I have in my application accomplished login/register authorization using tokens but am  storing my user credentials using the Identity framework and a Azure SQL DB (stored under dbo.AspNetUsers table that was created for me).</p>

<p>To go along with my users table I wish to have a table to actually store the metadata that is associated with my users, in my applications case:</p>

<blockquote>
  <ul>
  <li><p>Credit Card Information </p></li>
  <li><p>PDF files (in BLOB format, but multiple files associated with each account) These BLOB files are created when they upload a PDF and
  turned back into a PDF later when they download them.</p></li>
  </ul>
</blockquote>

<p>I see on the Azure Portal there is a Document NoSQL Database as well as BLOB storage. I wish to know if maybe I can add credit card information to my already existing AspNetUsers tables which could simplify me only having to deal with storing the PDF data in a seperate table by itself.</p>

<p>I am also unsure the structure of the table since one user can have many PDF files. My amateur knowledge thought that maybe having a Key Value database instead could be better in the format of:</p>

<pre><code>  Key-UserName            Value- JSON object of BLOB's with Id's.
</code></pre>

<p>I feel that for the PDF table on retrieving a BLOB representing a PDF it would not be best to retrieve all of them if I could associate an ID with each entry and figured a JSON object I could add as many fields as I wish to query on, but am unsure.</p>

<p>Obviously this is very premature and I am just looking for resources and experiences rather than a straight answer.</p>