完成课程文件实现层

server/internal/course_content/internal/model/coursecontentmodel_gen.go

@@ -28,6 +28,7 @@ type (
 		FindOne(ctx context.Context, id int64) (*CourseContent, error)
 		Update(ctx context.Context, data *CourseContent) error
 		Delete(ctx context.Context, id int64) error
+		FindByCourseAndParent(ctx context.Context, courseId, parentId int64) ([]*CourseContent, error)
 	}
 
 	defaultCourseContentModel struct {
@@ -84,6 +85,18 @@ func (m *defaultCourseContentModel) Update(ctx context.Context, data *CourseCont
 	return err
 }
 
+func (m *defaultCourseContentModel) FindByCourseAndParent(ctx context.Context, courseId, parentId int64) ([]*CourseContent, error) {
+	// 构造查询语句：按course_id和parent_id筛选，按sort升序排序
+	query := fmt.Sprintf("select %s from %s where `course_id` = ? and `parent_id` = ? order by `sort` asc", courseContentRows, m.table)
+	var contents []*CourseContent
+	// 执行查询（sqlx.QueryRowsCtx会自动将结果映射到结构体切片）
+	err := m.conn.QueryRowsCtx(ctx, &contents, query, courseId, parentId)
+	if err != nil {
+		return nil, err
+	}
+	return contents, nil
+}
+
 func (m *defaultCourseContentModel) tableName() string {
 	return m.table
 }