title: Firebase Query Or'ing whereEqualTo for a list of possible values
body: <p>I've seen <a href="https://stackoverflow.com/questions/26700924/query-based-on-multiple-where-clauses-in-firebase">this question before for an earlier version of Firebase</a> that is no longer applicable for Firebase Cloud Firestore.</p>
  
  <p>I would like to make a query that checks a document's field's value against a list of potential values, something like <code>whereEqualTo(someField, a OR b OR c OR ... OR n)</code>. Specifically, I have a list of potential values for a single field of type Reference and I want my query to return all documents in the specified collection whose value of the field is equal to one of the potential values in the list.  I am also using <code>.limit(10)</code> because I am paginating data.</p>
  
  <p>So for example, if my list contained the References [ref1, ref2, ref3] then the query would be similar to joining these 3 queries:</p>
  
  <p>Query query1 = mDatabase.collection("myCollection").whereEqualTo("refField", ref1);<br>
  Query query2 = mDatabase.collection("myCollection").whereEqualTo("refField", ref2);<br>
  Query query3 = mDatabase.collection("myCollection").whereEqualTo("refField", ref3);</p>
  
  <p>On the <a href="https://firebase.google.com/docs/firestore/query-data/queries" rel="nofollow noreferrer">documentation</a>, under the "Limitations" section, it mentions:</p>
  
  <p><code>Logical OR queries. In this case, you should create a separate query for each OR condition and merge the query results in your app.</code></p>
  
  <p>So maybe the best way would be to merge query results, but how could this be done, and with limiting to 10 results?</p>
  
  <p>Note that I am working with Java for Android Development.</p>