feat: add post buy count

backend/app/models/medias.go

@@ -198,3 +198,20 @@ func (m *mediasModel) GetByID(ctx context.Context, id int64) (*model.Medias, err
 
 	return &media, nil
 }
+
+// Delete
+func (m *mediasModel) Delete(ctx context.Context, id int64) error {
+	tbl := table.Medias
+	stmt := tbl.
+		DELETE().
+		WHERE(tbl.ID.EQ(Int64(id)))
+	m.log.Infof("sql: %s", stmt.DebugSql())
+
+	if _, err := stmt.ExecContext(ctx, db); err != nil {
+		m.log.Errorf("error deleting media item: %v", err)
+		return err
+	}
+
+	m.log.Infof("media item deleted successfully")
+	return nil
+}

backend/app/models/posts.go

@@ -233,3 +233,56 @@ func (m *postsModel) DeleteByID(ctx context.Context, id int64) error {
 	}
 	return nil
 }
+
+// SendTo
+func (m *postsModel) SendTo(ctx context.Context, userId, postId int64) error {
+	// add record to user_posts
+	tbl := table.UserPosts
+	stmt := tbl.INSERT(tbl.MutableColumns).MODEL(model.UserPosts{
+		UserID: userId,
+		PostID: postId,
+	})
+	m.log.Infof("sql: %s", stmt.DebugSql())
+	if _, err := stmt.ExecContext(ctx, db); err != nil {
+		m.log.Errorf("error sending post to user: %v", err)
+		return err
+	}
+	return nil
+}
+
+// PostBoughtStatistics 获取指定文件 ID 的购买次数
+func (m *postsModel) BoughtStatistics(ctx context.Context, postIds []int64) (map[int64]int64, error) {
+	tbl := table.UserPosts
+
+	// select count(user_id), post_id from user_posts up  where post_id in (1, 2,3,4,5,6,7,8,9,10) group by post_id
+	stmt := tbl.
+		SELECT(
+			COUNT(tbl.UserID).AS("cnt"),
+			tbl.PostID.AS("post_id"),
+		).
+		WHERE(
+			tbl.PostID.IN(lo.Map(postIds, func(id int64, _ int) Expression { return Int64(id) })...),
+		).
+		GROUP_BY(
+			tbl.PostID,
+		)
+	m.log.Infof("sql: %s", stmt.DebugSql())
+
+	var result []struct {
+		Cnt    int64
+		PostId int64
+	}
+
+	if err := stmt.QueryContext(ctx, db, &result); err != nil {
+		m.log.Errorf("error getting post bought statistics: %v", err)
+		return nil, err
+	}
+
+	// convert to map
+	resultMap := make(map[int64]int64)
+	for _, item := range result {
+		resultMap[item.PostId] = item.Cnt
+	}
+
+	return resultMap, nil
+}