SqlStorage Ionic 2 as a service/provider
<p>I have a provider in ionic two, and I have this:</p>

<pre><code>getCategory() {
    this.storage.query('SELECT * FROM category')
      .then((data) =&gt; {
        var category = [];
        if (data.res.rows.length &gt; 0) {
          for (var i = 0; i &lt; data.res.rows.length; i++) {
            category.push({
              name: data.res.rows.item(i).name,
              type: data.res.rows.item(i).type,
              note: data.res.rows.item(i).note
            });
          }
        }
        // console.log(JSON.stringify(category)); 
        return category; // is this correct?
      }, (error) =&gt; {
        console.log('Error -&gt; ' + JSON.stringify(error.err));
      });
  }
</code></pre>

<p>Then I wish to do something like this in my pages, after injecting the service:</p>

<pre><code>  constructor(nav, theservice) {
    this.nav = nav;
    this.service = theservice
    this.category = service.getCategory()
  }
</code></pre>

<p>How do I return something the results in order to be able to use? Trying the above returns nothing when I console log <code>this.category</code></p>

<p>The tutorial on <a href="https://www.thepolyglotdeveloper.com/2015/12/use-sqlite-in-ionic-2-instead-of-local-storage/" rel="nofollow">how to use sqlite in ionic 2</a> has been helpful, but couldn't figure out how to convert them into services/providers.</p>