title: Ruby: mysql throws error when using set function
body: <p>I do access a mysql database via mysql2 gem.</p>
  
  <p><code>conn.query("SET @showcurrent := false; SELECT * from admins;"</code>) </p>
  
  <p>throws me an error:</p>
  
  <pre><code>Mysql2::Error: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'SELECT * from admins' at line 1
  </code></pre>
  
  <p>if I exclude set function it works. How can I make it work with a <code>set</code> function?</p>
  
  <p><code>conn.query("SELECT * from admins;"</code>) </p>
  
  <pre><code>=&gt; #&lt;Mysql2::Result:0x00ff8557af200 @query_options={:as=&gt;:hash, :async=&gt;false, :cast_booleans=&gt;false, :symbolize_keys=&gt;false, :database_timezone=&gt;:local, :application_timezone=&gt;nil, :cache_rows=&gt;true, :connect_flags=&gt;bla, :cast=&gt;true, :default_file=&gt;nil, :default_group=&gt;nil, :host=&gt;"bla1", :username=&gt;"bla", :password=&gt;"bla", :database=&gt;"bla", :port=&gt;3007}&gt;
  </code></pre>