perf: reduce list query n+1

backend/app/services/tenant.go

@@ -36,13 +36,23 @@ func (s *tenant) List(ctx context.Context, filter *dto.TenantListFilter) (*reque
 		return nil, errorx.ErrDatabaseError.WithCause(err)
 	}
 
+	tenantIDs := make([]int64, 0, len(list))
+	for _, t := range list {
+		tenantIDs = append(tenantIDs, t.ID)
+	}
+
+	// 批量统计关注数与内容数，避免逐条 Count。
+	followerMap, err := s.countFollowers(ctx, tenantIDs)
+	if err != nil {
+		return nil, err
+	}
+	contentMap, err := s.countPublishedContents(ctx, tenantIDs)
+	if err != nil {
+		return nil, err
+	}
+
 	var data []dto.TenantProfile
 	for _, t := range list {
-		followers, _ := models.TenantUserQuery.WithContext(ctx).Where(models.TenantUserQuery.TenantID.Eq(t.ID)).Count()
-		contents, _ := models.ContentQuery.WithContext(ctx).
-			Where(models.ContentQuery.TenantID.Eq(t.ID), models.ContentQuery.Status.Eq(consts.ContentStatusPublished)).
-			Count()
-
 		cfg := t.Config.Data()
 		data = append(data, dto.TenantProfile{
 			ID:     t.ID,
@@ -50,8 +60,8 @@ func (s *tenant) List(ctx context.Context, filter *dto.TenantListFilter) (*reque
 			Avatar: cfg.Avatar,
 			Bio:    cfg.Bio,
 			Stats: dto.Stats{
-				Followers: int(followers),
-				Contents:  int(contents),
+				Followers: int(followerMap[t.ID]),
+				Contents:  int(contentMap[t.ID]),
 			},
 		})
 	}
@@ -159,29 +169,56 @@ func (s *tenant) ListFollowed(ctx context.Context, userID int64) ([]dto.TenantPr
 		return nil, errorx.ErrDatabaseError.WithCause(err)
 	}
 
+	if len(list) == 0 {
+		return []dto.TenantProfile{}, nil
+	}
+
+	tenantIDs := make([]int64, 0, len(list))
+	tenantIDSet := make(map[int64]struct{}, len(list))
+	for _, tu := range list {
+		if _, ok := tenantIDSet[tu.TenantID]; ok {
+			continue
+		}
+		tenantIDs = append(tenantIDs, tu.TenantID)
+		tenantIDSet[tu.TenantID] = struct{}{}
+	}
+
+	tblTenant, qTenant := models.TenantQuery.QueryContext(ctx)
+	tenants, err := qTenant.Where(tblTenant.ID.In(tenantIDs...)).Find()
+	if err != nil {
+		return nil, errorx.ErrDatabaseError.WithCause(err)
+	}
+
+	tenantMap := make(map[int64]*models.Tenant, len(tenants))
+	for _, t := range tenants {
+		tenantMap[t.ID] = t
+	}
+
+	// 批量统计关注数与内容数，避免逐条 Count。
+	followerMap, err := s.countFollowers(ctx, tenantIDs)
+	if err != nil {
+		return nil, err
+	}
+	contentMap, err := s.countPublishedContents(ctx, tenantIDs)
+	if err != nil {
+		return nil, err
+	}
+
 	var data []dto.TenantProfile
 	for _, tu := range list {
-		// Fetch Tenant
-		t, err := models.TenantQuery.WithContext(ctx).Where(models.TenantQuery.ID.Eq(tu.TenantID)).First()
-		if err != nil {
+		t, ok := tenantMap[tu.TenantID]
+		if !ok {
 			continue
 		}
 
-		// Stats
-		followers, _ := models.TenantUserQuery.WithContext(ctx).
-			Where(models.TenantUserQuery.TenantID.Eq(tu.TenantID)).
-			Count()
-		contents, _ := models.ContentQuery.WithContext(ctx).
-			Where(models.ContentQuery.TenantID.Eq(tu.TenantID), models.ContentQuery.Status.Eq(consts.ContentStatusPublished)).
-			Count()
-
+		cfg := t.Config.Data()
 		data = append(data, dto.TenantProfile{
 			ID:     t.ID,
 			Name:   t.Name,
-			Avatar: "",
+			Avatar: cfg.Avatar,
 			Stats: dto.Stats{
-				Followers: int(followers),
-				Contents:  int(contents),
+				Followers: int(followerMap[tu.TenantID]),
+				Contents:  int(contentMap[tu.TenantID]),
 			},
 			IsFollowing: true,
 		})
@@ -202,3 +239,52 @@ func (s *tenant) GetModelByID(ctx context.Context, id int64) (*models.Tenant, er
 	}
 	return u, nil
 }
+
+type tenantStatRow struct {
+	TenantID int64 `gorm:"column:tenant_id"`
+	Total    int64 `gorm:"column:total"`
+}
+
+func (s *tenant) countFollowers(ctx context.Context, tenantIDs []int64) (map[int64]int64, error) {
+	if len(tenantIDs) == 0 {
+		return map[int64]int64{}, nil
+	}
+
+	tbl, q := models.TenantUserQuery.QueryContext(ctx)
+	var rows []tenantStatRow
+	err := q.Where(tbl.TenantID.In(tenantIDs...)).
+		Select(tbl.TenantID, tbl.ALL.Count().As("total")).
+		Group(tbl.TenantID).
+		Scan(&rows)
+	if err != nil {
+		return nil, errorx.ErrDatabaseError.WithCause(err)
+	}
+
+	result := make(map[int64]int64, len(rows))
+	for _, row := range rows {
+		result[row.TenantID] = row.Total
+	}
+	return result, nil
+}
+
+func (s *tenant) countPublishedContents(ctx context.Context, tenantIDs []int64) (map[int64]int64, error) {
+	if len(tenantIDs) == 0 {
+		return map[int64]int64{}, nil
+	}
+
+	tbl, q := models.ContentQuery.QueryContext(ctx)
+	var rows []tenantStatRow
+	err := q.Where(tbl.TenantID.In(tenantIDs...), tbl.Status.Eq(consts.ContentStatusPublished)).
+		Select(tbl.TenantID, tbl.ALL.Count().As("total")).
+		Group(tbl.TenantID).
+		Scan(&rows)
+	if err != nil {
+		return nil, errorx.ErrDatabaseError.WithCause(err)
+	}
+
+	result := make(map[int64]int64, len(rows))
+	for _, row := range rows {
+		result[row.TenantID] = row.Total
+	}
+	return result, nil
+}