Spring Data Jpa的主要类
七个Repository接口：
1.Repository
2.CrudRepository
3.PagingAndSortingRepository
4.QueryByExampleExecutor
5.JpaRepository
6.JpaSpeccificationExecutor
7.QueryDslPredicateExecutor
两个实现类：
1.SimpleJpaRepository
2.QueryDslJpaRepository
*****
本框架中`JpaPlusRepository`实现了`JpaRepositoryImplementation`、`QuerydslPredicateExecutor` 在保留原方法基础上新增对`QueryDsl`的支持。
```
public interface JpaPlusRepository<T, ID> extends JpaRepositoryImplementation<T, ID>, QuerydslPredicateExecutor<T> {
T findOne(ID id);
Page<T> findAll(JPAQuery<T> query, Pageable pageable);
Page<T> findAll(JPAQuery<T> query, Pageable pageable, OrderSpecifier<?>... orders);
<S extends T> S insertOrUpdate(S entity);
<S extends T> List<S> insertOrUpdate(S... entities);
<S extends T> List<S> insertOrUpdate(List<S> entities);
int insertOrUpdateRow(T entity);
int insertOrUpdateRow(T... entities);
int insertOrUpdateRow(List<T> entities);
@Deprecated
int insert(T entity);
int update(T entity, Predicate... predicate);
int delete(ID... ids);
int delete(List<ID> ids);
int delete(Predicate... predicate);
}
```
### 依赖模块
```
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-data-jpa</artifactId>
</dependency>
```
### 启用注解
@EnableJpaPlusRepositories
```
@EnableJpaPlusRepositories
@SpringBootApplication
public class GotvApplication extends SpringBootServletInitializer {
public static void main(String[] args) {
SpringApplication app = new SpringApplication(GotvApplication.class);
app.run(args);
}
}
```
## 如何使用
### 1. 单表分页查询
```
@RequestMapping(value = "page")
public PaginationResult page(BaseVo base, PaginationVo page) {
// 对象
QSLog qsLog = QSLog.sLog;
// 条件
Predicate predicate = qsLog.id.isNotNull();
if (ObjectUtils.isNotEmpty(base.getKeyword())) {
Predicate p1 = qsLog.id.like("%" + base.getKeyword() + "%");
Predicate p2 = qsLog.method.likeIgnoreCase("%" + base.getKeyword() + "%");
Predicate p3 = qsLog.type.likeIgnoreCase("%" + base.getKeyword() + "%");
predicate = ExpressionUtils.and(predicate, ExpressionUtils.anyOf(p1, p2, p3));
}
// 排序
Sort sort = Sort.by(Direction.ASC, SLog.FIELDS.createDate);
// 分页
Pageable pageable = PageRequest.of(page.getPage(), page.getLimit(), sort);
// 查询
Page<SLog> data = mSLogRepository.findAll(predicate, pageable);
// 构造
return PaginationHelper.create(data);
}
```
### 2. 多表分页查询
```
@RequestMapping(value = "page")
public PaginationResult page(BaseVo base, PaginationVo page) {
// 对象
QUser qUser = QUser.user;
QSRole qRole = QSRole.sRole;
QUserRole qUserRole = QUserRole.userRole;
// 条件
Predicate predicate = qUser.id.isNotNull();
if (ObjectUtils.isNotEmpty(base.getKeyword())) {
Predicate p1 = qUser.id.like("%" + base.getKeyword() + "%");
Predicate p2 = qUser.username.likeIgnoreCase("%" + base.getKeyword() + "%");
Predicate p3 = qUser.nickname.likeIgnoreCase("%" + base.getKeyword() + "%");
predicate = ExpressionUtils.and(predicate, ExpressionUtils.anyOf(p1, p2, p3));
}
// 分页
Pageable pageable = PageRequest.of(page.getPage(), page.getLimit(), Sort.by(Direction.DESC, User.FIELDS.createDate));
// 查询字段
QBean<User> selectBean = Projections.fields(User.class
, qUse // 主表字段
, qRole.id.longValue().as(User.FIELDS.roleId), //联查字段
, qRole.name.as(User.FIELDS.roleName));
// 构造查询
JPAQuery<User> jpaQuery = mJPAQueryFactory.select(selectBean)
.from(qUser)
.leftJoin(qUserRole)
.on(qUser.id.eq(qUserRole.pk.users))
.leftJoin(qRole)
.on(qRole.id.eq(qUserRole.pk.roles))
.where(predicate);
// 分页查询
Page<User> data = mUserRepository.findAll(jpaQuery, pageable);
// 构造
return PaginationHelper.create(data);
}
```
### 3. 添加
```
@RequestMapping(value = "save")
@Transactional
public Result save(BaseVo base) {
User user = new User();
int row = mUserRepository.insertOrUpdate(user);
return (row >= 1) ? R.succ() : R.fail();
}
```
### 4. 修改
```
@RequestMapping(value = "update")
@Transactional
public Result update(BaseVo base) {
QUser qUser = QUser.user;
int row = (int) mJPAQueryFactory.update(qUser).set(qUser.isEnable, 1).where(qUser.id.in(base.getIds()));
return (row >= 1) ? R.succ() : R.fail();
}
```
### 5. 删除
```
@RequestMapping(value = "delete")
@Transactional
public Result delete(BaseVo base) {
int row = mUserRepository.delete(base.getIds());
return (row >= 1) ? R.succ() : R.fail();
}
```
上述只是部分示例，拓展后常规方法共48个
### 属性表达式
| 关键字 | 示例 | JPQL 片段 |
| --- | --- | --- |
| And | findByNameAndAge | where x.name = ?1 and x.age = ?2 |
| Or | findByNameOrAge | where x.name = ?1 or x.age = ?2 |
| Is | findByNameIs | where x.name = ?1 |
| Equals | findByNameEquals | where x.name = ?1 |
| Between | findByStartDateBetween | where x.startDate between ?1 and ?2 |
| LessThan | findByAgeLessThan | where x.age < ?1 |
| LessThanEqual | findByAgeLessThanEqual | where x.age ⇐ ?1 |
| GreaterThan | findByAgeGreaterThan | where x.age > ?1 |
| GreaterThanEqual | findByAgeGreaterThanEqual | where x.age >= ?1 |
| After | findByStartDateAfter | where x.startDate > ?1 |
| Before | findByStartDateBefore | where x.startDate < ?1 |
| IsNull | findByAgeIsNull | where x.age is null |
| IsNotNull | findByAgeIsNotNull | where x.age not null |
| NotNull | findByAgeNotNull | where x.age not null |
| Like | findByNameLike | where x.name like ?1 |
| NotLike | findByNameNotLike | where x.name not like ?1 |
| StartingWith | findByNameStartingWith | where x.name like ?1 (parameter bound with appended %) |
| EndingWith | findByNameEndingWith | where x.name like ?1 (parameter bound with prepended %) |
| Containing | findByNameContaining | where x.name like ?1 (parameter bound wrapped in %) |
| OrderBy | findByAgeOrderByNameDesc | where x.age = ?1 order by x.name desc |
| Not | findByNameNot | where x.name <> ?1 |
| In | findByAgeIn(Collectionages) | where x.age in ?1 |
| NotIn | findByAgeNotIn(Collectionage) | where x.age not in ?1 |
| TRUE | findByActiveTrue() | where x.active = true |
| FALSE | findByActiveFalse() | where x.active = false |
| IgnoreCase | findByNameIgnoreCase | where UPPER(x.name) = UPPER(?1) |
