1、理解Specification： Specification在Spring Data JPA中用于封装JPA Criteria查询条件，提供灵活的条件组合和动态查询能力。2、创建Specification实现： 通过实现Specification接口，定义具体的查询条件逻辑，可以根据需要组合不同的Predicate条件。3、使用CriteriaBuilder构建查询条件： 在Specification实现中，利用CriteriaBuilder来构...
*/ fun <S : EntityType, ResultType> findBy(spec: Specification<EntityType>, queryFunction: (FluentQuery.FetchableFluentQuery<S>) -> ResultType): ResultType /** * Returns all instances of the type [EntityType] with the given IDs. * * If some or all ids are not found, no entities...
@Query("select u from User u where u.firstname = ?1 and u.firstname=?#{[0]} and u.emailAddress = ?#{principal.emailAddress}") List<User> findByFirstnameAndCurrentUserWithCustomQuery(String firstname); 对于like-conditions,人们通常希望附加%到字符串值参数的开头或结尾。这可以通过附加或前缀...
importorg.springframework.data.repository.CrudRepository;publicinterfaceUserRepositoryextendsJpaRepository<T, I>, JpaSpecificationExecutor<T>{//Custom query method exampleList<User>findByUsername(String username); } 5,使用repository接口 在服务类中注入Repository并使用它进行数据库操作: importorg.springframework...
Section 10.3.1 "NamedQuery Annotation" in the JPA Specification (http://jcp.org/en/jsr/detail?id=317) batch Useeclipselink.batchto supply EclipseLink with batching information so subsequent queries of related objects can be optimized in batches, instead of being retrieved one-by-one or in one...
然后改写MovieRepository,为了让Repository可以运行Specification,我们需要让其继承JpaSpecificationExecutor接口。 Copy publicinterfaceMovieRepositoryextendsJpaRepository<Movie, Long>, JpaSpecificationExecutor<Movie> {// query methods here} 然后我们就可以愉快的使用定义好的Specification了。
复杂查询需要额外使用Specification 如果两张表都是双向多对多关系,那么我想根据教师查出学生名字等于“学生3”的Student集合,这时就需要 Specification<Teacher> specification = Specification.where((root, query, cb) -> { Join<Teacher, student> join = root.join("student", JoinType.LEFT); ...
Compatible with Spring Data JPA and JPA 2.1 interface.Equal/NotEqual/Like/NotLike/In/NotIn support multiple values, Equal/NotEqual support Null value.Each specification support join query(left joiner).Support custom specification.Builder style specification creator.Support pagination and sort builder.2...
JpaSpecificationExecutor:用来做负责查询的接口 Specification:是Spring Data JPA提供的一个查询规范,要做复杂的查询,只需围绕这个规范来设置查询条件即可。 题外话:刚开始,其实我看mybatis提供的都差不多,最让我觉得神奇的是:可以通过方法命名规则进行相关数据库操作,这个确实可以减少很多代码的编写。原本使用Mybatis-plu...
Last modified: 17 June 2024 Required plugin:Jakarta EE: Persistence (JPA)(bundled) Jakarta Persistence(JPA), formerly known as Java Persistence API, is a Java specification for managing relational data inJava Enterpriseapplications. This functionality relies on theJakarta EE: Persistence (JPA)...