title: nodejs express mysql query with 'SET @'XXX''
body: <p>I am working on nodejs/express app. In my routes i need to query data from MySQL database. It's working fine with exceptions for the queries that have parameters in them.
  Any query without parameters work as expected:</p>
  
  <pre><code>SELECT * FROM table WHERE col = 'b'
  </code></pre>
  
  <p>But the one below returns <code>undefined</code></p>
  
  <pre><code> SET @a = 'b'
   SELECT * FROM table where col = @a
  </code></pre>
  
  <p>I generate string for queries in separate function (not sure if that makes any difference).
  Any help will be greatly appreciated.</p>