Develop Reference

Max number of results from GraphQL

I am working on a project with GraphQL-java and Hibernate with MariaDB.
In my current solution, I get 18938 results back. I just want to see the last 10 of these. So I am looking for a solution to limit the number of results.
On the internet I see examples of limiting the number of results (https://graphql.org/learn/pagination/). They call it pagination. However, I cannot find the server implementation of this. Does anyone have experience with this?
I have an Entity class, with some properties : Test.java
#Entity
#Table(name = "test")
public class Test {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
private Long id;
#NotNull
#Size(max = 64)
#Column(nullable = false)
private String name;
#ManyToOne(fetch = FetchType.LAZY)
#JoinColumn(name = "parent")
private Test parent;
public Test() {
}
public Long getId() {
return id;
}
public void setId(Long id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public Test getParent() {
return parent;
}
public void setParent(Test parent) {
this.parent = parent;
}
My repository class: TestRepository.java
public interface TestRepository extends CrudRepository<Test, Integer> {}
My GraphQL resolver class: Query.java
#Component
public class Query implements GraphQLQueryResolver {
private TestRepository testRepository;
#Autowired
public Query(TestRepository testRepository) {
this.testRepository = testRepository;
}
public Iterable<Test> findAllTests(Integer first) {
return testRepository.findAll();
}
public long countTests() {
return testRepository.count();
}
}
My GraphQL schema: test.graphqls
type Test {
id: ID!
name: String!
parent: Test
}
#extend query
type Query {
findAllTests(first: Int): [Test]!
countTests: Int!
}

To summarize my last comment here is what I would do:
Instead of extending CrudRepository, extend PagingAndSortingRepository (which is extending CrudRepository)
public interface TestRepository extends PagingAndSortingRepository<Test, Integer> {
}
In your Query class pass two args to findAllTests method, page and size that will be used to create the Pageable object
#Component
public class Query implements GraphQLQueryResolver {
// other properties & methods are omitted for brevity
public Iterable<Test> findAllTests(Integer page, Integer size) {
Pageable pageable = PageRequest.of(page, size);
return testRepository.findAll(pageable).getContent(); // findAll returns Page and we can get the underlying List with getContent
}
}
Add two params from above in your GraphQL schema (I set default page size to be 20)
#extend query
type Query {
findAllTests(page: Int = 0, size: Int = 20): [Test]!
countTests: Int!
}
Since I have no experience with GraphQL, I'm not sure if this works, but you can give me feedback if there are some problems.

DuplicateKeyException: error code 11000 and error message 'E11000'

i want to update/replace document using id field only, i am using mongoTemplate.save(p, collection) method but i am getting DuplicateKeyException: error code 11000 and error message 'E11000'
public class MongoDAO {
#Autowired
#Qualifier("mongoTemplate")
private MongoTemplate mongoTemplate;
private static final String PERSON_COLLECTION = "person";
public MongoTemplate getMongoTemplate() {
return mongoTemplate;
}
public void update(Object p) {
this.mongoTemplate.save(p, PERSON_COLLECTION);
}
}
This is my person DAO
public class PersonDAO{
#Autowired
MongoDAO mongoDAO;
public void updatePerson(){
//read
Person p1 = mongoDAO.readById("1234");
//update
p1.setName("David");
mongoDAO.update(p1);
}
}
Person.java class
package com.mongo.andy;
import org.springframework.data.annotation.Id;
import org.springframework.data.mongodb.core.mapping.Field;
public class Person {
#Id
private String id;
#Field
private String name;
public String getId() {
return id;
}
public void setId(String id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
}
I simply want to get the object from mongodb change the values and update the document based on _id
Using mongooperation.save() or mongotemplate.save() i am getting below error
com.mongodb.DuplicateKeyException: Write failed with error code 11000 and error message 'E11000 duplicate key error collection: Person.person index: _id_ dup key: { : "5996f1d43b6af5c797a1cf4g" }'
at com.mongodb.operation.BaseWriteOperation.convertBulkWriteException(BaseWriteOperation.java:236)
at com.mongodb.operation.BaseWriteOperation.access$300(BaseWriteOperation.java:60)
at com.mongodb.operation.BaseWriteOperation$1.call(BaseWriteOperation.java:146)
at com.mongodb.operation.BaseWriteOperation$1.call(BaseWriteOperation.java:133)
at com.mongodb.operation.OperationHelper.withConnectionSource(OperationHelper.java:230)
at com.mongodb.operation.OperationHelper.withConnection(OperationHelper.java:221)
at com.mongodb.operation.BaseWriteOperation.execute(BaseWriteOperation.java:133)
at com.mongodb.operation.BaseWriteOperation.execute(BaseWriteOperation.java:60)
at com.mongodb.Mongo.execute(Mongo.java:781)
at com.mongodb.Mongo$2.execute(Mongo.java:764)
at com.mongodb.DBCollection.executeWriteOperation(DBCollection.java:333)
at com.mongodb.DBCollection.insert(DBCollection.java:328)
at com.mongodb.DBCollection.insert(DBCollection.java:319)
at com.mongodb.DBCollection.insert(DBCollection.java:289)
at com.mongodb.DBCollection.insert(DBCollection.java:255)
at com.mongodb.DBCollection.insert(DBCollection.java:192)
at org.springframework.data.mongodb.core.MongoTemplate$9.doInCollection(MongoTemplate.java:1051)
at org.springframework.data.mongodb.core.MongoTemplate.execute(MongoTemplate.java:479)
at org.springframework.data.mongodb.core.MongoTemplate.insertDBObject(MongoTemplate.java:1046)
at org.springframework.data.mongodb.core.MongoTemplate.doInsert(MongoTemplate.java:855)
at org.springframework.data.mongodb.core.MongoTemplate.doSaveVersioned(MongoTemplate.java:1001)
at org.springframework.data.mongodb.core.MongoTemplate.save(MongoTemplate.java:985)
at com.mcmcg.dia.account.metadata.dao.MongoDAO.update(MongoDAO.java:105)
at com.mcmcg.dia.account.metadata.service.AccountOALDService.mongotestapi(AccountOALDService.java:265)
at com.mcmcg.dia.account.metadata.service.AccountOALDService$$FastClassBySpringCGLIB$$7f85f843.invoke(<generated>)
Please provide the solution and suggest if there is any other way to update/replace documents in mongodb using spring-data on the basis of id field only. I have large custom object and not interesting writing any queries for update.
I was able to do so in couchbase db using upsert(), finding similar way in mongodb.

Instead of this.mongoTemplate.save(p, PERSON_COLLECTION); try with:
public void update(Object p) {
BasicDBObject dbObject = new BasicDBObject();
mongoTemplate.getConverter().write(p, dbObject);
mongoTemplate.upsert(new Query(Criteria.where("_id").is(((Person) p).getId())),
Update.fromDBObject(dbObject, "_id"), PERSON_COLLECTION);
}
The solution is similar to how the upsert method it is implemented in MongoTemplate.

Java Spring REST API Status 400 response on POST / PUT

I built a REST API Service using Java Spring Cloud / Boot. Firstly, I made a simple class connected to a MongoDB and a controller with service that should allow me to add, delete, update and get all the objects. When using POSTMAN these all work, however when I want to add or update an object using redux and fetch API I get a status 400 and "bad request" error. This seems to have something to do with the JSON I'm sending in the body but it is the exact same format of JSON that is working with for example POSTMAN.
My action in Redux. For simplicity / test purposes I added an object at the top in stead of using the object being sent from the page.
var assetObject = {
"vendor" : "why dis no work?",
"name": "wtf",
"version": "231",
"category" : "qsd",
"technology" : "whatever"
}
export function addAsset(access_token, asset) {
return dispatch => {
fetch(constants.SERVER_ADDRESS + '/as/asset/add',
{
method: 'POST',
credentials: 'include',
headers: {
'Authorization': 'Bearer' + access_token,
'Content-Type': 'application/json'
},
body: assetObject
})
.then(res => dispatch({
type: constants.ADD_ASSET,
asset
}))
}
}
Controller code in Java Spring:
#RequestMapping(method = RequestMethod.POST, path = "/add")
public void addAsset(#RequestBody Asset asset) {
assetService.addAsset(asset);
}
Status ok while doing it in postman:
The error I get when using Redux / Fetch API (I only removed the directory structure because it has company name in it):
Have been stuck on this for a while, any help is much appreciated!
EDIT Asset Object:
import org.springframework.data.annotation.Id;
import org.springframework.data.mongodb.core.mapping.Document;
#Document(collection = "assets")
public class Asset {
#Id
private String id;
private String vendor;
private String name;
private String version;
private String category;
private String technology;
public Asset() {
}
public Asset(String id,
String vendor,
String name,
String version,
String category,
String technology) {
this.id = id;
this.vendor = vendor;
this.name = name;
this.version = version;
this.category = category;
this.technology = technology;
}
public String getId() {
return id;
}
public String getVendor() {
return vendor;
}
public String getName() {
return name;
}
public String getVersion() {
return version;
}
public String getCategory() {
return category;
}
public String getTechnology() {
return technology;
}
public void setId(String id) {
this.id = id;
}
public void setVendor(String vendor) {
this.vendor = vendor;
}
public void setName(String name) {
this.name = name;
}
public void setVersion(String version) {
this.version = version;
}
public void setCategory(String category) {
this.category = category;
}
public void setTechnology(String technology) {
this.technology = technology;
}
}

your error message says :
; required request body is missing
i think the error happens when your controller method
trying to form an object from the incoming request.
when you are sending the request you have to set each and every field related to the object.
if you are planning on not setting a property you should mark that field with #JsonIgnore annotation.
you can use #JsonIgnore annotation on the variable which will ignore this property
when forming the object as well as when outputing the object.
use #JsonIgnore annotation on the setter method , which i think you should do now since
you are ignoring the id property when making the request.
#JsonIgnore
public void setId(String id) {
this.id = id;
}
and you can return httpstatus code from the controller method,
so that client knows request was successful
#ResponseBody
public ResponseEntity<String> addAsset(#RequestBody Asset asset) {
return new ResponseEntity<String>("your response here", HttpStatus.OK);
}

Error while binding form request play-framework 2.5.4

I am using play-framework-java 2.5.4.
I want to bind a user-input-from values to my model class variables.
This is my controller function that except form POST :
public Result formSubmit()
{
MlmModel mlmModel;
play.data.Form<MlmModel> form = play.data.Form.form(MlmModel.class).bindFromRequest();
mlmModel = form.get();
mlmModel.save();
mlmModel.callUpdate();
return ok(Json.toJson(mlmModel));
}
But I am getting this error
[CompletionException: java.lang.IllegalStateException: Error(s) binding form: {"parent_id":["Invalid value"]}]
because, one of my input field is not compulsory to fill by user.
It's fine if user left blank some fields.
But my code should
save all data that user provides to database and
should save 0 by default for the fields left blank by user .
I am Using play-Eben and my database server is MySQL 5.x
How can I achieve this?
Edit 1 :
MlmModel.java
#Entity
public class MlmModel extends Model
{
#Id
#GeneratedValue()
public Long ID;
public Logic logic;
public MlmModel() {
this.parent_id = 0;
logic = new Logic(this);
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String name;
public long getParent_id() {
return parent_id;
}
public void setParent_id(long parent_id) {
if (String.valueOf(parent_id).isEmpty())
this.parent_id = 0;
this.parent_id = parent_id;
}
#Column(columnDefinition = "long default 0")
public long parent_id;
#Formats.DateTime(pattern="dd/MM/yyyy")
public Date created_time = new Date();
public Long balance = new Long(0);
public static Finder<Long, MlmModel> find = new Finder<Long,MlmModel>(MlmModel.class);
public List<ValidationError> validate()
{
List<ValidationError> errors = new ArrayList<ValidationError>();
if (Long.toString(parent_id).isEmpty())
parent_id = 0;
if (errors.isEmpty())
return null;
else
return errors;
}
}

Is it possible to use raw SQL within a Spring Repository

I need to use raw SQL within a Spring Data Repository, is this possible? Everything I see around #Query is always entity based.

The #Query annotation allows to execute native queries by setting the nativeQuery flag to true.
Quote from Spring Data JPA reference docs.
Also, see this section on how to do it with a named native query.

YES, You can do this in bellow ways:
1. By CrudRepository (Projection)
Spring Data Repositories usually return the domain model when using query methods. However, sometimes, you may need to alter the view of that model for various reasons.
Suppose your entity is like this :
import javax.persistence.*;
import java.math.BigDecimal;
#Entity
#Table(name = "USER_INFO_TEST")
public class UserInfoTest {
private int id;
private String name;
private String rollNo;
public UserInfoTest() {
}
public UserInfoTest(int id, String name) {
this.id = id;
this.name = name;
}
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
#Column(name = "ID", nullable = false, precision = 0)
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
#Basic
#Column(name = "name", nullable = true)
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
#Basic
#Column(name = "roll_no", nullable = true)
public String getRollNo() {
return rollNo;
}
public void setRollNo(String rollNo) {
this.rollNo = rollNo;
}
}
Now your Projection class is like below. It can those fields that you needed.
public interface IUserProjection {
int getId();
String getName();
String getRollNo();
}
And Your Data Access Object(Dao) is like bellow :
import org.springframework.data.jpa.repository.Query;
import org.springframework.data.repository.CrudRepository;
import java.util.ArrayList;
public interface UserInfoTestDao extends CrudRepository<UserInfoTest,Integer> {
#Query(value = "select id,name,roll_no from USER_INFO_TEST where rollNo = ?1", nativeQuery = true)
ArrayList<IUserProjection> findUserUsingRollNo(String rollNo);
}
Now ArrayList<IUserProjection> findUserUsingRollNo(String rollNo) will give you the list of user.
2. Using EntityManager
Suppose your query is "select id,name from users where roll_no = 1001".
Here query will return an object with id and name column. Your Response class is like bellow:
Your Response class is like this:
public class UserObject{
int id;
String name;
String rollNo;
public UserObject(Object[] columns) {
this.id = (columns[0] != null)?((BigDecimal)columns[0]).intValue():0;
this.name = (String) columns[1];
}
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getRollNo() {
return rollNo;
}
public void setRollNo(String rollNo) {
this.rollNo = rollNo;
}
}
here UserObject constructor will get an Object Array and set data with the object.
public UserObject(Object[] columns) {
this.id = (columns[0] != null)?((BigDecimal)columns[0]).intValue():0;
this.name = (String) columns[1];
}
Your query executing function is like bellow :
public UserObject getUserByRoll(EntityManager entityManager,String rollNo) {
String queryStr = "select id,name from users where roll_no = ?1";
try {
Query query = entityManager.createNativeQuery(queryStr);
query.setParameter(1, rollNo);
return new UserObject((Object[]) query.getSingleResult());
} catch (Exception e) {
e.printStackTrace();
throw e;
}
}
Here you have to import bellow packages:
import javax.persistence.Query;
import javax.persistence.EntityManager;
Now your main class, you have to call this function. First get EntityManager and call this getUserByRoll(EntityManager entityManager,String rollNo) function. The calling procedure is given below:
Here is the Imports
import javax.persistence.EntityManager;
import javax.persistence.PersistenceContext;
get EntityManager from this way:
#PersistenceContext
private EntityManager entityManager;
UserObject userObject = getUserByRoll(entityManager,"1001");
Now you have data in this userObject.
Note:
query.getSingleResult() return a object array. You have to maintain the column position and data type with the query column position.
select id,name from users where roll_no = 1001
query return a array and it's [0] --> id and [1] -> name.
More info visit this thread and this Thread
Thanks :)

It is possible to use raw query within a Spring Repository.
#Query(value = "SELECT A.IS_MUTUAL_AID FROM planex AS A
INNER JOIN planex_rel AS B ON A.PLANEX_ID=B.PLANEX_ID
WHERE B.GOOD_ID = :goodId",nativeQuery = true)
Boolean mutualAidFlag(#Param("goodId")Integer goodId);

we can use createNativeQuery("Here Native SQL Query ");
for Example :
Query q = em.createNativeQuery("SELECT a.firstname, a.lastname FROM Author a");
List<Object[]> authors = q.getResultList();

This is how you can use in simple form
#RestController
public class PlaceAPIController {
#Autowired
private EntityManager entityManager;
#RequestMapping(value = "/api/places", method = RequestMethod.GET)
public List<Place> getPlaces() {
List<Place> results = entityManager.createNativeQuery("SELECT * FROM places p limit 10").getResultList();
return results;
}
}

It is also possible to use Spring Data JDBC, which is a fully supported Spring project built on top of Spring Data Commons to access to databases with raw SQL, without using JPA.
It is less powerful than Spring Data JPA, but if you want lightweight solution for simple projects without using a an ORM like Hibernate, that a solution worth to try.