SDN 6 custom query returns NULL

[amirkanan]

Hi there,

I am tring to return the subset of a domain entity (e.g ItemEntity) with a costom query using SDN 6 and SpringBoot 2.5. It is returning NULL without any error when I run the application.

I tried the same query in Neo4j Browser and works fine.

How that issue could be solved?

Below is a sample of the code where I face this issue

Thanks in advance for your help.
Amir

package org.website.gui.repository;

import org.website.gui.entity.ItemEntity;
import org.website.gui.projection.ItemSubset;
import org.springframework.data.neo4j.repository.Neo4jRepository;
import org.springframework.data.neo4j.repository.query.Query;

import java.util.Date;
import java.util.List;

public interface ItemRepository extends Neo4jRepository<ItemEntity, Integer> {

    @Query("MATCH (i:Item)"
            + " WHERE toLower (COALESCE(i.firstField,\" \")"
            + ") CONTAINS $englishKeyword"
            + " OR "
            + "COALESCE(i.secondField,\" \")"
            + "CONTAINS $russianKeyword"
            + " RETURN i"
    )
    List<ItemSubset> findWithKeywords(String englishKeyword, String russianKeyword);

[gerrit_meier]

Would be really helpful to see your domain entity ItemEntity and the ItemSubset.
ItemSubset should be a valid projection as defined here reference documentation | projections.

Does this really return null or an empty list?

[amirkanan]

Hi @gerrit.meier

Thank you for your quick respond.

It returns an empty JSON Array. Something like [ ].

Please find code sample below:

package org.website.gui.entity;

import lombok.AllArgsConstructor;
import lombok.Data;
import org.springframework.data.neo4j.core.schema.Id;
import org.springframework.data.neo4j.core.schema.Node;
import org.springframework.data.neo4j.core.schema.Property;
import org.springframework.data.neo4j.core.schema.Relationship;

import java.time.LocalDate;


@Node("Item")
@AllArgsConstructor
@Data
public class ItemEntity {
    @Id
    private final Integer id;
    private final LocalDate active_date;
    @Property("empty_sapce")
    private final String firstField;
    private final String secondField;
    private final String thirdField;
    @Relationship(type = "HANDLED_BY")
    private final TaskEntity task;
}

//--------ItemSubset--------

package org.website.gui.projection;

public interface ItemSubset {
    Integer getId();
    String getFirstField();
    String getSecondField();
}

Many thanks,
A

[gerrit_meier]

Could you checkout my example: neo4j-issues-examples/discourse-42200 at master · meistermeier/neo4j-issues-examples · GitHub
This works for me.

In your custom query you use toLower only on the english part not on the russian one. Might this be a problem?

[amirkanan]

Thank you @gerrit.meier !
I have changed the custom query based on your suggestion but I still have the sam problem (no data returned).

How can I work around this problem?

Many thanks,
A

    @Query("MATCH (i:Item)"
            + " WHERE toLower (COALESCE(i.e_ops,\" \")"
            + ") CONTAINS $englishKeyword"
            + " OR "
            + "toLower (COALESCE(i.r_ops,\" \")"
            + ") CONTAINS $russianKeyword"
            + " RETURN i"
    )
    List<ItemSubset> findVariousKeywords(String englishKeyword, String russianKeyword);

[gerrit_meier]

I don't know what you are doing different to my example.
Maybe you can spot the difference between my code and your application around this place where you are facing the issue.

[amirkanan · Accepted solution]

Thank you @gerrit.meier .

I have checked the example and changed the spring-boot-strarter-parent version from 2.5.0 to 2.5.3.

    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.5.3</version> <!-- it was 2.5.0 -->
        <relativePath/> <!-- lookup parent from repository -->
    </parent>

It is working now. I do not know how this upgrade was related to my issue!!!

Cheers,
A