title: how can i get run sql like 'show create table xxx' in knexjs
body: <p>is there anyone know how to run sql like 'show create table xxx' in knex.js?
  And how can i get the result?</p>
  <p>write like this ?</p>
  <pre class="lang-js prettyprint-override"><code>knex.schema.raw('show create table xxx');
  </code></pre>
  <p>and another question how to write &quot;replace into &quot; in knexjs?</p>