网站底部的备案信息,网站维护具体做啥,网站空间2G一年多少钱,自己做游戏网站八、JpaSpecificationExecutor接口 前言#xff1a;该接口主要提供了多条件查询的支持#xff0c;并且可以在查询中添加分页和排序。 注意#xff1a;JpaSpecificationExecutor接口是独立存在的。完全独立。 1、持久层接口#xff1a;
public interface UsersRepositoryS…八、JpaSpecificationExecutor接口 前言该接口主要提供了多条件查询的支持并且可以在查询中添加分页和排序。 注意JpaSpecificationExecutor接口是独立存在的。完全独立。 1、持久层接口
public interface UsersRepositorySpecification extends JpaRepositoryUsers,Integer, JpaSpecificationExecutorUsers {
}测试代码
RunWith(SpringRunner.class)
SpringBootTest
public class UsersRepositorySpecificationTest {Autowiredprivate UsersRepositorySpecification usersRepositorySpecification;/*** jpaSpecificationExecutor 接口 单条件测试*/Testpublic void jpaSpecificationExecutor() {/*** SpecificationUsers 用于封装条件*/SpecificationUsers spec new SpecificationUsers() {/*** RootUsers:查询对象属性封装* CriteriaQuery? query:疯长了我们要执行的查询中各个部分的信息select from order* CriteriaBuilder:查询条件的构造器定义不同查询条件* param root* param query* param criteriaBuilder* return*/Overridepublic Predicate toPredicate(RootUsers root, CriteriaQuery? query, CriteriaBuilder criteriaBuilder) {/*** 参数1查询的属性* 参数2查询的指*/Predicate pre criteriaBuilder.equal(root.get(name), zhanga);return pre;}};ListUsers list usersRepositorySpecification.findAll(spec);for (Users users : list) {System.out.println(users);}}/*** jpaSpecificationExecutor 接口 多条件测试*/Testpublic void jpaSpecificationExecutor2() {/*** SpecificationUsers 用于封装条件*/SpecificationUsers spec new SpecificationUsers() {/*** RootUsers:查询对象属性封装* CriteriaQuery? query:疯长了我们要执行的查询中各个部分的信息select from order* CriteriaBuilder:查询条件的构造器定义不同查询条件* param root* param query* param criteriaBuilder* return*/Overridepublic Predicate toPredicate(RootUsers root, CriteriaQuery? query, CriteriaBuilder criteriaBuilder) {/*** where namezhanga and age 20* 参数2查询的指*/ListPredicate list new ArrayList();list.add(criteriaBuilder.equal(root.get(name), zhanga));list.add(criteriaBuilder.equal(root.get(age), 22));Predicate[] arr new Predicate[list.size()];return criteriaBuilder.and(list.toArray(arr));}};ListUsers list usersRepositorySpecification.findAll(spec);for (Users users : list) {System.out.println(users);}}/*** jpaSpecificationExecutor 接口 多条件测试2*/Testpublic void jpaSpecificationExecutor3() {/*** SpecificationUsers 用于封装条件*/SpecificationUsers spec new SpecificationUsers() {/*** RootUsers:查询对象属性封装* CriteriaQuery? query:疯长了我们要执行的查询中各个部分的信息select from order* CriteriaBuilder:查询条件的构造器定义不同查询条件* param root* param query* param cb* return*/Overridepublic Predicate toPredicate(RootUsers root, CriteriaQuery? query, CriteriaBuilder cb) {/*** where namezhanga and age 20* 参数2查询的指*/
// ListPredicate list new ArrayList();
// list.add(criteriaBuilder.equal(root.get(name), zhanga));
// list.add(criteriaBuilder.equal(root.get(age), 22));
// Predicate[] arr new Predicate[list.size()];//只有and
// return cb.and(cb.equal(root.get(name),zhanga),cb.equal(root.get(age),22));//只有or
// return cb.or(cb.equal(root.get(name),zhanga),cb.equal(root.get(age),22));//andor//namezhanga and age22 or id 2 and 的优先级高于or 相当于//(namezhanga and age22) or id 2return cb.or(cb.equal(root.get(name), zhanga), cb.equal(root.get(age), 22), cb.equal(root.get(id), 2));}};//添加排序规则Sort sort new Sort(new Sort.Order(Sort.Direction.DESC, id));ListUsers list usersRepositorySpecification.findAll(spec, sort);for (Users users : list) {System.out.println(users);}}
}本文源码下载 github地址 https://github.com/gb-heima/Spring-Boot-Actual-Combat/tree/master/parent/spring-boot-chapter-9
