Add support for QueryDSL and Query by Example projections through a fluent API in repositories

[spring-projects-issues]

marcusvoltolim opened DATACMNS-1813 and commented

https://jira.spring.io/browse/DATAJPA-1796

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Affects: 2.3.4 (Neumann SR4)

Reference URL: https://jira.spring.io/browse/DATAJPA-1796

[mp911de]

See also:

• Add support for QueryDSL projections in JPA repositories [DATAJPA-1796] spring-data-jpa#2090
• Dynamic projections in combination with Specifications and Pagination not working [DATAJPA-1189] spring-data-jpa#1524
• Enable usage of projections in QueryDslPredicateExecutor [DATAJPA-1119] spring-data-jpa#1463
• Support projections on query methods that take a dynamic query type (Specification or Querydsl Predicate) [DATAJPA-1033] spring-data-jpa#1378
• Provide spring data query dsl repository for FactoryExpression with Predicate and Pageable for selecting specified columns [DATACMNS-383] #853
• QuerydslDataFetcher to specify which properties and associations to fetch spring-graphql#87

As we face strong demand from various angles (Querydsl/Query-by-Example/JPA Specifications with projections, pagination queries, GraphQL to define eagerly loaded associations), we want to explore means how to define queries that leverage already existing base technology and are able to provide a certain degree of flexibility known from store-specific API (stream consumption, projections, inclusion/exclusion of properties).

[dhunganawork]

This feature addition was very helpful. However, project() method does not seem to work. Or I might be doing somethin wrong.
Below is my code snippet. I want to select id column only, but my hibernate sql log shows all columns are being selected.

Page alerts = myRepository.findBy(predicate,
ffq -> ffq
.project("id")
.as(MyProjection.class)
.page(pageable)

    );

[paulocagol]

Esta adição de recurso foi muito útil. No entanto, o método project () parece não funcionar. Ou posso estar fazendo algo errado. Abaixo está o meu trecho de código. Quero selecionar apenas a coluna id, mas meu log sql do hibernate mostra que todas as colunas estão sendo selecionadas.

Alertas de página = myRepository.findBy(predicado, ffq -> ffq .project("id") .as(MyProjection.class) .page(pageable)

    );

The same here