fix: complete exploration data flow

backend/internal/models/dataset_cron.go

@@ -14,8 +14,8 @@ type SaDatasetCron struct {
 	Enabled           bool   `gorm:"not null;default:true;index"`
 	NextRunAt         *time.Time
 	LastRunAt         *time.Time
-	LastResult        string `gorm:"type:text"`
-	CreatedAt         time.Time
+	LastResult        string    `gorm:"type:text"`
+	CreatedAt         time.Time `gorm:"index"`
 	UpdatedAt         time.Time
 }
 

backend/internal/models/identity.go

@@ -2,6 +2,7 @@ package models
 
 import (
 	"database/sql"
+	"errors"
 
 	"github.com/google/uuid"
 	"gorm.io/gorm"
@@ -28,6 +29,9 @@ func (m *SaDatasetSource) BeforeCreate(tx *gorm.DB) error {
 	if m.CreatedBy == 0 {
 		m.CreatedBy = m.OwnerID
 	}
+	if m.OwnerID == 0 {
+		return errors.New("dataset source owner is required")
+	}
 	if err := resolveIdentity(tx, &SaUser{}, m.OwnerID, &m.OwnerIdentity); err != nil {
 		return err
 	}