Question

我在Spring Boot项目中使用JPA规范。所有标准都运行良好。但是问题出在选择/多选。

代码-

@AllArgsConstructor
public class TodoSpecifications implements Specification<Todo> {
@Override
  public Predicate toPredicate(
      Root<todoEntity> root, CriteriaQuery<?> query, CriteriaBuilder criteriaBuilder) {
    List<Predicate> predicateList = createPredicateList(root, criteriaBuilder);


    List<Selection<? extends Object>> selectionList = new ArrayList<Selection<? extends Object>>();
      Selection<? extends Object> selection = root.get("id");
      selectionList.add(selection);
    Selection<? extends Object> selection2 = root.get("name");
    selectionList.add(selection2);
    Selection<? extends Object> selection3 = root.get("type");
    selectionList.add(selection3);

    return query.multiselect(selectionList).where(criteriaBuilder.and(predicateList.toArray(new Predicate[] {}))).getRestriction();
  }
}

使用此规范，我尝试了列出toDoEntity = todoRepository.findAll（todoSpecification）; 这将返回完整数据。但是我只希望选择的列。

Answer 1

您是否有采用3个参数的构造函数？为了能够使用多选，您必须像这样在TodoEntity中创建一个构造函数

public TodoEntity (Long id, String name, String type) {
this.id = id;
this.name =  name;
this.type = type;
}

Select / MultiSelect在JPA（春季启动）中不起作用

1 个答案: