Version: 0.2.2.dev.260210

feat: 🗑️ 新增删除任务块接口

- 实现 schedules、schedule_events 与 task_items 三表的联动删除
- 保证数据一致性，避免遗留脏数据 ✅

backend/dao/schedule.go

@@ -397,3 +397,50 @@ func (d *ScheduleDAO) SetScheduleEmbeddedTaskIDToNull(ctx context.Context, event
 	}
 	return embeddedTaskID, nil
 }
+
+func (d *ScheduleDAO) FindEmbeddedTaskIDAndDeleteIt(ctx context.Context, taskID int) (int, error) {
+	// 1. 先找到 schedules 表中 embedded_task_id = taskID 的记录，获取对应的 event_id
+	type row struct {
+		EventID *int `gorm:"column:event_id"`
+	}
+	var r row
+	err := d.db.WithContext(ctx).
+		Table("schedules").
+		Select("event_id").
+		Where("embedded_task_id = ?", taskID).
+		Order("id ASC").
+		Limit(1).
+		Scan(&r).Error
+	if err != nil {
+		return 0, err
+	}
+	if r.EventID == nil {
+		return 0, respond.TargetTaskNotEmbeddedInAnySchedule
+	}
+	eventID := *r.EventID
+
+	// 2. 删除该 event_id 对应的课程事件（通过级联删除实现）
+	res := d.db.WithContext(ctx).
+		Table("schedule_events").
+		Where("id = ?", eventID).
+		Delete(&model.ScheduleEvent{})
+	if res.Error != nil {
+		return 0, res.Error
+	}
+	if res.RowsAffected == 0 {
+		return 0, respond.TargetTaskNotEmbeddedInAnySchedule
+	}
+	return eventID, nil
+}
+
+func (d *ScheduleDAO) DeleteScheduleEventByTaskItemID(ctx context.Context, taskItemID int) error {
+	//直接找schedule_events表中type=task且rel_id=taskItemID的记录，删除它（级联删schedules）
+	res := d.db.WithContext(ctx).
+		Table("schedule_events").
+		Where("type = ? AND rel_id = ?", "task", taskItemID).
+		Delete(&model.ScheduleEvent{})
+	if res.Error != nil {
+		return res.Error
+	}
+	return nil
+}

backend/dao/task-class.go

@@ -2,6 +2,7 @@ package dao
 
 import (
 	"context"
+	"errors"
 
 	"github.com/LoveLosita/smartflow/backend/model"
 	"github.com/LoveLosita/smartflow/backend/respond"
@@ -158,12 +159,15 @@ func (dao *TaskClassDAO) GetTaskClassItemByID(ctx context.Context, id int) (*mod
 
 func (dao *TaskClassDAO) GetTaskClassIDByTaskItemID(ctx context.Context, itemID int) (int, error) {
 	var item model.TaskClassItem
-	err := dao.db.WithContext(ctx).
+	res := dao.db.WithContext(ctx).
 		Select("category_id").
 		Where("id = ?", itemID).
-		First(&item).Error
-	if err != nil {
-		return 0, err
+		First(&item)
+	if res.Error != nil {
+		if errors.Is(res.Error, gorm.ErrRecordNotFound) {
+			return 0, respond.TaskClassItemNotFound
+		}
+		return 0, res.Error
 	}
 	return *item.CategoryID, nil
 }
@@ -207,3 +211,10 @@ func (dao *TaskClassDAO) IfTaskClassItemArranged(ctx context.Context, taskID int
 	}
 	return item.EmbeddedTime != nil, nil
 }
+
+func (dao *TaskClassDAO) DeleteTaskClassItemByID(ctx context.Context, id int) error {
+	err := dao.db.WithContext(ctx).
+		Where("id = ?", id).
+		Delete(&model.TaskClassItem{}).Error
+	return err
+}