Tag: mongodb

Indexed
This annotation marks the field as indexed in MongoDB

@QueryEntity
@Document
public class User {
    @Indexed
    private String name;
     
    ... 
}

Compound Indexes
MongoDB supports compound indexes, where a single index structure holds references to multiple fields.

@QueryEntity
@Document
@CompoundIndexes({
    @CompoundIndex(name = "email_age", def = "{'email.id' : 1, 'age': 1}")
})
public class User {
    //
}

Transient
As you would expect, this simple annotation excludes the field from being persisted in the database.

public class User {
     
    @Transient
    private Integer yearOfBirth;
    // standard getter and setter
 
}

Field
@Field indicates the key to be used for the field in the JSON document

@Field("email")
private EmailAddress emailAddress;

References
http://www.baeldung.com/spring-data-mongodb-index-annotations-converter

Test Data

> db.users.find()
{ "_id" : ObjectId("id"), "ic" : "1001", "name" : "ant", "age" : 10 }
{ "_id" : ObjectId("id"), "ic" : "1002", "name" : "bird", "age" : 20 }
{ "_id" : ObjectId("id"), "ic" : "1003", "name" : "cat", "age" : 30 }
{ "_id" : ObjectId("id"), "ic" : "1004", "name" : "dog", "age" : 40 }
{ "_id" : ObjectId("id"), "ic" : "1005", "name" : "elephant", "age" : 50 }
{ "_id" : ObjectId("id"), "ic" : "1006", "name" : "frog", "age" : 60 }

BasicQuery example

BasicQuery query1 = new BasicQuery("{ age : { $lt : 40 }, name : 'cat' }");
User userTest1 = mongoOperation.findOne(query1, User.class);

System.out.println("query1 - " + query1.toString());
System.out.println("userTest1 - " + userTest1);

findOne example

Query query2 = new Query();
query2.addCriteria(Criteria.where("name").is("dog").and("age").is(40));

User userTest2 = mongoOperation.findOne(query2, User.class);
System.out.println("query2 - " + query2.toString());
System.out.println("userTest2 - " + userTest2);

find and $inc example

List<Integer> listOfAge = new ArrayList<Integer>();
listOfAge.add(10);
listOfAge.add(30);
listOfAge.add(40);

Query query3 = new Query();
query3.addCriteria(Criteria.where("age").in(listOfAge));

List<User> userTest3 = mongoOperation.find(query3, User.class);
System.out.println("query3 - " + query3.toString());

for (User user : userTest3) {
	System.out.println("userTest3 - " + user);
}

find and $gt, $lt, $and example

Query query4 = new Query();
query4.addCriteria(Criteria.where("age").lt(40).and("age").gt(10));

List<User> userTest4 = mongoOperation.find(query4, User.class);
System.out.println("query4 - " + query4.toString());

for (User user : userTest4) {
	System.out.println("userTest4 - " + user);
}

You can’t use Criteria.and() to add multiple criteria into the same field, to fix it, use Criteria.andOperator(), see updated example :

Query query4 = new Query();
query4.addCriteria(
	Criteria.where("age").exists(true)
	.andOperator(
		Criteria.where("age").gt(10),
                Criteria.where("age").lt(40)
	)
);

List<User> userTest4 = mongoOperation.find(query4, User.class);
System.out.println("query4 - " + query4.toString());

for (User user : userTest4) {
	System.out.println("userTest4 - " + user);
}

find and sorting example

Query query5 = new Query();
query5.addCriteria(Criteria.where("age").gte(30));
query5.with(new Sort(Sort.Direction.DESC, "age"));

List<User> userTest5 = mongoOperation.find(query5, User.class);
System.out.println("query5 - " + query5.toString());

for (User user : userTest5) {
	System.out.println("userTest5 - " + user);
}

find and $regex example

Query query6 = new Query();
query6.addCriteria(Criteria.where("name").regex("D.*G", "i"));

List<User> userTest6 = mongoOperation.find(query6, User.class);
System.out.println("query6 - " + query6.toString());

for (User user : userTest6) {
	System.out.println("userTest6 - " + user);
}

Method 2 : Generated Query Methods

public interface UserRepository 
  extends MongoRepository<User, String>, QueryDslPredicateExecutor<User> {
    ...
}

References
https://www.mkyong.com/mongodb/spring-data-mongodb-query-document/
http://www.baeldung.com/queries-in-spring-data-mongodb