title: how to query a blob data
body: <p>I have a table like :</p>
  
  <pre><code>------------------------------
  Test_Id           Test_data
  (String)          (blob)
  ------------------------------
  </code></pre>
  
  <p>I want a query to retrieve all the Test_Id's for a matching Test_data.</p>
  
  <p>To achieve something like : select * from test_table where Test_data = blobObject;</p>
  
  <p>How can we do above ??</p>