How to use 'or' operator in the queries?

Questions & Feedback
1

How to use ‘or’ operator in the queries?

2

Hi! This is not currently possible.

The Guild joined The Graph as a core developer team, and they are currently working on this and other features. If you are interested, they talked about this during the last community talk. The Graph’s Community Talk #6 - YouTube (timestamped)

A workaround would be to use aliases. You will be able to retrieve all results in a single query, but you will not be able to sort across the “root queries”

{
   q1: books (where: {category_contains: "Math"}) {
   ...
   }
   q2: books (where: {category_contains: "Sci-Fi"}) {
   ...
   } 
   q3: books (where: {category_contains: "Subgraphs"}) {
   ...
   }  
}