title: How can I query in psql. If column name like camelCase
body: <p>My psql table structure like below:</p>
  
  <pre><code>id userName gender  
  1   xxxx     Male
  </code></pre>
  
  <p>if I am using query like below from psql shell:    </p>
  
  <pre><code>select * from table where userName="xxx";
  </code></pre>
  
  <p>It gives error: 
  Error: column <strong>"userName"</strong> does not exists.</p>
  
  <p>How can I query if column name contain with <strong>camelCase</strong>.</p>