Spring data mongo use OR in Query

Or if you are using a Criteria API

Criteria criteria = new Criteria();
criteria.orOperator(Criteria.where("A").is(10),Criteria.where("B").is(20));
Query query = new Query(criteria);

mongoOps.find(query, <Yourclass>.class, "collectionName");

In addition to helloJava answer, If you already have query with other criteria's you can add orOperation directly on query.addCriteria as below.

query.addCriteria(new Criteria().orOperator(Criteria.where("fieldA").is(value),
                Criteria.where("fieldB").is(value2)));

You can use Spring Data MongoDB like this:

Query query = new Query();
query.addCriteria(
    Criteria.where("").orOperator(
        Criteria.where("A").is(10),
        Criteria.where("B").is(20)
    )
);

mongoTemplate.find(query, YourClazz.class, "CollectionName");

I think this might work

@Query("{'$or':[ {'A':10}, {'B':20} ] }")