backend/src/main/java/nju/seec/helper/dao/CourseDAO.java

package nju.seec.helper.dao;

import nju.seec.helper.entity.Course;
import nju.seec.helper.util.enums.ExceptionType;
import nju.seec.helper.util.exception.HelperException;
import org.springframework.data.domain.Page;
import org.springframework.data.domain.Pageable;
import org.springframework.data.jpa.repository.JpaRepository;
import org.springframework.data.jpa.repository.Modifying;
import org.springframework.data.jpa.repository.Query;
import org.springframework.stereotype.Repository;
import org.springframework.transaction.annotation.Transactional;

import java.util.Set;

/**
 * @author cst
 */
@Repository
public interface CourseDAO extends JpaRepository<Course, Long> {
    /**
     * 封装findById
     *
     * @param id
     * @return
     */
    default Course findCourseById(Long id) {
        return this.findById(id)
                .filter(course -> course.getDeleteAt() == 0)
                .orElseThrow(() -> HelperException.of(ExceptionType.NOT_FOUND, "找不到课程"));
    }

    /**
     * 检查老师是否已创建同名课程
     *
     * @param teacherId
     * @param name
     * @param courseId
     * @return
     */
    @Query("select case when count(c.id)>0 then true else false end " +
            "from Course c " +
            "where c.id<>?1 " +
            "and c.teacherId=?2 " +
            "and c.name=?3 " +
            "and c.deleteAt=0 ")
    boolean existsByTeacherIdAndName(Long courseId, Long teacherId, String name);

    /**
     * 查询老师创建的课程
     *
     * @param teacherId
     * @param key
     * @param pageable
     * @return
     */
    @Query("select c from Course c " +
            "where c.teacherId=?1 " +
            "and c.name like concat('%',?2,'%') " +
            "and c.deleteAt=0 ")
    Page<Course> findByTeacherIdAndKey(Long teacherId, String key, Pageable pageable);

    /**
     * 查询课程
     *
     * @param key
     * @param pageable
     * @return
     */
    @Query("select c from Course c " +
            "where (c.name like concat('%',?1,'%') or c.teacherName like concat('%',?1,'%')) " +
            "and c.deleteAt=0 ")
    Page<Course> findByKey(String key, Pageable pageable);

    /**
     * 按ID列表查询
     *
     * @param courseIds
     * @param key
     * @param pageable
     * @return
     */
    @Query("select c from Course c " +
            "where c.id in ?1 " +
            "and (c.name like concat('%',?2,'%') or c.teacherName like concat('%',?2,'%')) " +
            "and c.deleteAt=0 ")
    Page<Course> findByIdsAndKey(Set<Long> courseIds, String key, Pageable pageable);

    /**
     * 更新所有人信息
     *
     * @param userId
     * @param userName
     */
    @Transactional(rollbackFor = Exception.class)
    @Modifying
    @Query("update Course c " +
            "set c.teacherName=?2 " +
            "where c.teacherId=?1 ")
    void updateUser(Long userId, String userName);
}