spring jpa查询问题

2017-12-01 04:09:42 398 阅读 AI 写同款 · GEO 优化AI 选题数据监测一键分发 ›

关于Spring-Data-JPA只查询部分字段返回对象集合问题记录关于Spring-Data-JPA只查询部分字段返回对象集合问题记录。阅读详情

@Test
public void test(){
System.out.println("Start testing");

Specification<TOrder> specification = new Specification<TOrder>() {
@Override
public Predicate toPredicate(Root<TOrder> root, CriteriaQuery<?> query, CriteriaBuilder cb) {
List<Predicate> predicateList = new ArrayList<>();

Predicate orderNo = cb.equal(root.get("orderNo").as(String.class), "1001");
Predicate payStatusLike = cb.like(root.get("payStatus"), "已支付");
Predicate orderNoIsNotEmpty = cb.isNotEmpty(root.get("orderNo"));

Predicate[] pre = new Predicate[predicateList.size()];
//predicateList.add(orderNo);
//predicateList.add(payStatusLike);
predicateList.add(orderNoIsNotEmpty);

//query.where(predicateList.toArray(pre));

//return query.getRestriction();
return cb.and(predicateList.toArray(pre));
}
};
List<TOrder> orders = tOrderDao2.findAll(specification);
System.out.println(JSONValue.toJSONString(orders));
}

运行报一下错误:
org.springframework.dao.InvalidDataAccessApiUsageException: unknown collection expression type [org.hibernate.jpa.criteria.path.SingularAttributePath]; nested exception is java.lang.IllegalArgumentException: unknown collection expression type [org.hibernate.jpa.criteria.path.SingularAttributePath]
搞了半天也没出来
cb.isNotEmpty(root.get("orderNo"));
这个参数该怎么传 ?

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