在 MYSQL AND 条件中使用 Java 谓词

Question

我有以下基于 java predicate 的代码，它从我的 MYSQL 数据库中获取结果列表：

Root<Person> from = query.from(Person.class);
CriteriaQuery<Person> selectQuery = query.select(from);
List<Person> searchResults = new ArrayList<>();

Predicate jobPredicate = createPersonJobPredicate();
Predicate agePredicate = createPersonAgePredicate(); //currently not used

selectQuery = selectQuery.where(jobPredicate);
searchResults =entityManager.createQuery(selectQuery).setFirstResult(searchRequest.getIndex()).setMaxResults(searchRequest.getSize()).getResultList();

我想做的是更改上面的代码，以便结果列表必须匹配 both 谓词 - 例如必须是 job - "doctor" AND age - 45

我试过像下面这样组合谓词，但这总是 returns 工作谓词：

selectQuery = selectQuery.where(jobPredicate).where(agePredicate);

我该怎么做？

Answer 1

试试这样的东西：

CriteriaBuilder criteriaBuilder = entityManager.getCriteriaBuilder();
CriteriaQuery<Person> criteriaQuery = criteriaBuilder.createQuery(Person.class);
Root<Person> personRoot = criteriaQuery.from(Person.class);

Predicate jobPredicate = criteriaBuilder.equal(personRoot.get("job"), "doctor");
Predicate agePredicate = criteriaBuilder.greaterThan(personRoot.get("age"), 45);

Predicate combinedPredicate = criteriaBuilder.and(jobPredicate, agePredicate);
criteriaQuery.where(combinedPredicate);
List<Person> searchResults = 
   entityManager.createQuery(criteriaQuery).getResultList();

在 MYSQL AND 条件中使用 Java 谓词

Using Java Predicates in MYSQL AND condition

java

mysql

predicate

arraylist

criteriaquery