I'm trying to deserialise a one to many association with JooQ (without code generation) as per this post.
Here are my target classes.
public class Author {
private Long id;
private String name;
private List<Book> books;
}
public class Book {
private String name;
}
My JooQ query is as follows:
dslContext
.select(table("authors").asterisk(),
field(
select(jsonArrayAgg(
jsonObject(
jsonEntry("name", field("books.name")))))
.from(table("books"))
.join(table("authors"))
.on(field("books.author_id").eq(field("authors.id")))
.where(field("emails.collection_case_id")
.eq(field("collection_cases.id")))
).as("books"))
.from(table("authors"))
.where(trueCondition())
.fetchInto(Author.class);
The jsonObject() method does not work as expected for me. The generated SQL statement looks something like this:
select authors.*, (select json_agg(json_build_object(?, books.name)) from books join authors ...
The translated postgres query has not properly replaced the key attribute of json_build_object and this results in SQL exception.
PS: I'm using JooQ 3.14.0 with postgres 11.5
While I can't reproduce this issue on my side with various PostgreSQL server and JDBC driver versions, the simple workaround here is to use DSL.inline(String) to prevent jOOQ's generating a bind variable for the json_build_object() function argument:
jsonEntry(inline("name"), field("books.name"))
Related
I am using Spring Data JDBC (v1.1.1) automatically pulled in by SpringBoot 2.2.1.RELEASE. For the repository below, the method should automatically derive the Query at start-up time.
interface AccountRepository extends CrudRepository<Account, Long> {
long countByLastName(String lastName);
...
Instead I get this..
Caused by: java.lang.IllegalStateException: No query specified on countByLastName
at org.springframework.data.jdbc.repository.support.JdbcRepositoryQuery.determineQuery(JdbcRepositoryQuery.java:200) ~[spring-data-jdbc-1.1.1.RELEASE.jar:1.1.1.RELEASE]
My entity looks like..
public class Account {
#Id
private Long id;
private final String firstName;
private final String lastName;
Any idea why I am getting this issue?
Support for query derivation for Spring Data JDBC came with version 2.0.0.
Note that query derivation currently only supports properties which get stored in the table of the aggregate root for filtering and sorting.
I recently asked this question : Spring Mongodb - Insert Nested document?
And found out that Spring-Data-MongoDB does not support such behavior - so now I need a working alternative.
Now - to avoid having you look at the code on another page, I am going to paste it here from the other question... Here are my two POJOs :
#Document
public class PersonWrapper {
#Id
private ObjectId _Id;
#DBRef
private Person leader;
#DBRef
List<Person> delegates;
// Getters and setters removed for brevity.
}
public class Person
{
#Id
private ObjectId _Id;
private String name;
// Getters and setters removed for brevity.
}
Now, what I want to be able to do here - is send up a JSON object in my POST request as follows :
{
"personWrapper":
{
"_Id":"<ID HERE (MIGHT WANT SQL TO GENERATE THIS DURING CREATE>",
"leader":{
"_Id":"<ID HERE (MIGHT WANT SQL TO GENERATE THIS DURING CREATE>",
"name":"Leader McLeaderFace"
},
delegates:[{...},{...},{...}]
}
}
At this point - I would like the SQL side of this to create the individual records needed - and then insert the PersonWrapper record, with all of the right foreign keys to the desired records, in the most efficient way possible.
To be honest, if one of you thinks I am wrong about the Spring-Data-MongoDB approach to this, I would still be interested in the answer - because it would save me the hassle of migrating my database setup. So I will still tag the spring-data-mongodb community here, too.
If I understand well you want to cascade the save of your objects ?
ex : you save a PersonWrapper with some Person in the delegates property and spring data will save PersonneWrapper in a collection and save also the list of Person in another Collection.
It is possible to do that with Spring DATA JPA if you annotate your POJO with the JPA annotation #OneToMany and setup cascade property of this annotation. See this post
However the cascade feature is not available for Spring DATA mongoDB. See documentation .First you have to save the list of Person and then you save PersonWrapper.
I am trying to run a native query on a repository method so that it returns the results with some counts. It was too complicated to do with JPQL, so I opted for a native query instead.
Repository
#RepositoryRestResource(collectionResourceRel="projects", path="projects")
interface ProjectRepository extends BaseRepository<Project, Long>, ProjectRepositoryCustom {
#Query(
value="SELECT p.id, p.user_id, p.title, p.description, p.created_on, p.version,(SELECT COUNT(0) FROM projectparts WHERE project_id = p.id) AS parts,(SELECT COUNT(0) FROM requests WHERE project_id = p.id) AS requests FROM projects AS p ORDER BY ?#{#pageable}",
countQuery="SELECT COUNT(0) FROM projects",
nativeQuery=true
)
Page<Project> findAll(Pageable pageable)
}
The entity has 2 properties annotated with #Transient so that the info is not persisted to the database. All the data comes back fine except the 2 transient properties which return null for the values. When I copy the query from the console and paste it in MySQL Workbench, the results are as expected and I see the counts that I need. Anyhow, not sure if there is anything else that needs to be done in order to get this native query to work as an annotation. I hard coded a value in the sub-query SELECT 55 FROM... just to see if it was a problem with the count and it still returned as null. I ran the query in Workbench and it works fine.
I've tried changing the transient property type from Integer, Long, BigInteger, long, int... and none of that made a difference. Since I'm using Groovy, I also tried def to let Groovy infer the type and that didn't work either.
I also tried running the project from the terminal instead and it still didn't work. I've tried it on a Mac and Linux and had no luck with displaying the results of the counts.
This will not work. You could use an SQLConstructorExpression however the returned instances would be unmanaged which is a major drawback.
An better option is to create a simple DB view which holds the pieces of summary info for the Project. You can them map the Project entity to both it's table and the associated summary view using the #SecondaryTable functionality of JPA.
https://en.wikibooks.org/wiki/Java_Persistence/Tables#Example_mapping_annotations_for_an_entity_with_multiple_tables
An added benefit is that you can sort and query on the summary values as for any other property.
Updated mapping:
#Entity
#Table(name = "projects")
#SecondaryTable(name = "projects_summary_vw")
public class Project{
//use Integer rather than int to avoid issue outlined here:
//http://stackoverflow.com/a/37160701/1356423
#Column(name = "parts", table = "projects_summary_vw",
insertable="false", updateable="false")
private Integer partsCount;
#Column(name = "requests", table = "requestsCount"
insertable="false", updateable="false")
private Integer requestsCount;
//other mappings as required
}
No Custom query required:
#RepositoryRestResource(collectionResourceRel="projects",
path="projects")
interface ProjectRepository extends BaseRepository<Project, Long>,
ProjectRepositoryCustom {
}
An alternative non-JPA compliant solution may be to use some vendor specific extension rather than a view. Hibernate for example has an #Formula annotation which could be used:
https://docs.jboss.org/hibernate/orm/5.1/javadocs/org/hibernate/annotations/Formula.html
#Entity
#Table(name = "projects")
public class Project{
#Formula("my count query as native sql")
private Integer partsCount;
#Formula("my count query as native sql")
private Integer requestsCount;
//other mappings as required
}
I'm trying to get a page of a partial entity (NetworkSimple) using the new feature of spring data, projections
I've checked the documentation and if I request only:
Collection<NetworkSimple> findAllProjectedBy();
It works, but if I'm using pageable:
Page<NetworkSimple> findAllProjectedBy(Pageable pageable);
It throws an error:
org.hibernate.jpa.criteria.expression.function.AggregationFunction$COUNT cannot be cast to org.hibernate.jpa.criteria.expression.CompoundSelectionImpl
Any one has already work with this ?
My NetworkSimple class is the following:
public interface NetworkSimple {
Long getId();
String getNetworkName();
Boolean getIsActive();
}
Note: This feature should work in the way described by the original poster but due to this bug it didn't. The bug has been fixed for the Hopper SR2 release, if you're stuck on an earlier version then the workaround below will work.
It is possible to use Pageable with the new query projection features introduced in Spring Data JPA 1.10 (Hopper). You will need to use the #Query annotation and manually write a query for the fields you require, they must also be aliased using AS to allow Spring Data to figure out how to project the results. There is a good example in spring-boot-samples part of the spring boot repository.
In your example it would be quite simple:
#Query("SELECT n.id AS id, n.name AS networkName, n.active AS isActive FROM Network n")
Page<NetworkSimple> findAllProjectedBy(Pageable pageable);
I have made the assumption that your entity looks something like this:
#Entity
public class Network
{
#Id
#GeneratedValue
private Long id;
#Column
private String name;
#Column
private boolean active;
...
}
Spring Data will derive a count query automatically for the paging information. It is also possible to make use of joins in the query to fetch associations and then summarise them in the projection.
I think you need create findAllProjectedBy() as specification.Then you can use findAll() method like this.
example :findAll(findAllProjectedBy(),pageable)
Following link may be help to find how to create specification in spring.
https://spring.io/blog/2011/04/26/advanced-spring-data-jpa-specifications-and-querydsl/
The issue may come from the method name. The by keyword means that you ae filterig data by a specific property: findByName for example. Its called query creation from method name:
http://docs.spring.io/spring-data/jpa/docs/1.10.1.RELEASE/reference/html/#repositories.query-methods.query-creation
So try with Page<NetworkSimple> findAll(Pageable pageable);
Even with spring-data-jpa 1.11.4, something like
public interface NetworkRepository extends JpaRepository<Network, String> {
Page<NetworkSimple> findAll(Pageable pageable);
}
would not compile; reporting
findAll(org.springframework.data.domain.Pageable) in NetworkRepository clashes with findAll(org.springframework.data.domain.Pageable) in org.springframework.data.repository.PagingAndSortingRepository
return type org.springframework.data.domain.Page<NetworkSimple> is not compatible with org.springframework.data.domain.Page<Network>
The workaround we found was to rename findAll to findAllBy, e.g.
public interface NetworkRepository extends JpaRepository<Network, String> {
Page<NetworkSimple> findAllBy(Pageable pageable);
}
You can use interface projection with Pageable like this :
Page<NetworkSimple> findPagedProjectedBy(Pageable pageable);
with some parameter :
Page<NetworkSimple> findPagedProjectedByName(String name, Pageable pageable);
Implementing interface projection with pagination
1. Our ResourceEntity.java class
#Getter
#Setter
#NoArgsConstructor
#Entity
public class ResourceEntity{
private Long id;
private String name;
}
2. Creating projection Interface name ProjectedResource.java, which maps data collected by the SQL query from repository layer method
public interface ProjectedResource {
Long getId();
String getName();
String getAnotherProperty();
}
3. Creating Repository layer method: getProjectedResources()
We are considering the database table name is resource.
We are only fetching id and name here.
#Query(name="select id, name, anotherProperty from resource", countQuery="select count(*) from resource", nativeQuery=true)
Page<ProjectedResource> getProjectedResources(Pageable page);
Hope the issue will be resolved!
You can use:
#Query("SELECT n FROM Network n")
Page<? extends NetworkSimple> findAllProjectedBy(Pageable pageable);
I am using spring-data-jpa version 1.5.1.RELEASE .
My domain is :
public class MyDomain{
....
....
private String prop1;
private String prop2;
......
......
}
My JPA Specification is:
public final class MyDomainSpecs {
public static Specification<MyDomain> search(final String prop1,final String prop2) {
return new Specification<MyDomain>() {
public Predicate toPredicate(Root<MyDomain> root, CriteriaQuery<?> query, CriteriaBuilder cb) {
// Some tests if prop1 exist .....
Predicate predicate1 = cb.equal(root.get("prop1"), prop1);
Predicate predicate2 = cb.equal(root.get("prop2"), prop2);
return cb.and(predicate1, predicate2);
}
};
}
}
My Repository :
public interface MyDomainRepository extends JpaRepository<MyDomain, Long>, JpaSpecificationExecutor<MyDomain> {
List<MyDomain> findAll(Specification<MyDomain> spec);
}
All is Working .
But my need (For performance DB tunning) is to not return and select all fields of MyDomain from DB .
I need to select only for example tree properties (prop1, prop2, prop3) , idealy in a DTO Object .
I don't want to convert My List<MyDomain> to List<MyDto> because i am tunning DB request .
So , I don't find any way to do that with spring-data-Jpa and Specification .
Any Idea ?
Thanks
This is not possible as for now. There is a ticket for this but no idea if it will be ever implmented: https://jira.spring.io/browse/DATAJPA-51
Create a special version of MyDomain (e.g. MyDomainSummary or LightMyDomain) that only includes the fields you want to map.
Basic example
Borrowed from the excellent JPA WikiBook.
Assume a JPA entity (i.e. domain class) like so:
#Entity
#Table(name="EMPLOYEE")
public class BasicEmployee {
#Column(name="ID")
private long id;
#Column(name="F_NAME")
private String firstName;
#Column(name="L_NAME")
private String lastName;
// Any un-mapped field will be automatically mapped as basic and column name defaulted.
private BigDecimal salary;
}
The SQL query generated will be similar to
SELECT ID, F_NAME, L_NAME, SALARY FROM EMPLOYEE
if no conditions (where clause) are defined. So, to generalize the basic case one can say that the number of queried columns is equal to the number of mapped fields in your entity. Therefore, the fewer fields your entity, the fewer columns included in the SQL query.
You can have an Employee entity with e.g. 20 fields and a BasicEmployee as above with only 4 fields. Then you create different repositories or different repository methods for both.
Performance considerations
However, I seriously doubt you'll see noticeable performance improvements unless the fields you want to omit represent relationships to other entities. Before you start tweaking here log the SQL that is currently issued against the data base, then remove the columns you want to omit from that SQL, run it again and analyze what you gained.