Spring Data Mongo查询字段参数

Question

I'm playing with Spring Data Mongo Query and wondering about the field property parameters. Here is the example that I got from the documentation :

public interface PersonRepository extends MongoRepository<Person, String>
  @Query(value="{ 'firstname' : ?0 }", fields="{ 'firstname' : 1, 'lastname' : 1}")
  List<Person> findByThePersonsFirstname(String firstname);
}

The question is: What is the meaning of 1 in { 'firstname' : 1, 'lastname' : 1} ?

Answer 1

1 means that both 'firstname' and 'lastname' will be included in the resulted document. For example, if you have 'salary' field you can exclude it from result by typing 'salary': 0 .

Answer 2

You can use MongoTemplate for querying.First you declare query and after that you can declare criteria .Below is an example :

Criteria criteria = Criteria.where("kademeler.isemriId").is(isemriNo)
                .and("ogag").is(1);
        Query query = new Query(criteria);
        query.fields().exclude("salary"); //for excluding a field, this is "salary" for you
        List<AboneAriza> result = mongoTemplate.find(query, AboneAriza.class);

Answer 3

只是要添加，默认情况下也会返回文档的ID，因此，这将意味着返回名字，姓氏以及文档的_id，并且由于已经回答将字段设置为零，因此不会返回该ID。返回文档时的特定字段。