一阶段ok

internal/store/attachment_store.go

@@ -0,0 +1,59 @@
+package store
+
+import (
+	"mail_go/internal/db"
+
+	"gorm.io/gorm"
+)
+
+// AttachmentStore defines the interface for attachment data operations.
+type AttachmentStore interface {
+	Create(att *db.Attachment) error
+	GetByID(id uint) (*db.Attachment, error)
+	ListByMessage(messageID uint) ([]db.Attachment, error)
+	Delete(id uint) error
+	DeleteByMessage(messageID uint) error
+}
+
+// attachmentStoreGorm implements AttachmentStore using GORM.
+type attachmentStoreGorm struct {
+	db *gorm.DB
+}
+
+// newAttachmentStore creates a new GORM-backed AttachmentStore.
+func newAttachmentStore(database *gorm.DB) AttachmentStore {
+	return &attachmentStoreGorm{db: database}
+}
+
+// Create inserts a new attachment record.
+func (s *attachmentStoreGorm) Create(att *db.Attachment) error {
+	return s.db.Create(att).Error
+}
+
+// GetByID retrieves an attachment by primary key.
+func (s *attachmentStoreGorm) GetByID(id uint) (*db.Attachment, error) {
+	var att db.Attachment
+	if err := s.db.First(&att, id).Error; err != nil {
+		return nil, err
+	}
+	return &att, nil
+}
+
+// ListByMessage retrieves all attachments for a given message.
+func (s *attachmentStoreGorm) ListByMessage(messageID uint) ([]db.Attachment, error) {
+	var attachments []db.Attachment
+	if err := s.db.Where("message_id = ?", messageID).Find(&attachments).Error; err != nil {
+		return nil, err
+	}
+	return attachments, nil
+}
+
+// Delete removes an attachment by ID.
+func (s *attachmentStoreGorm) Delete(id uint) error {
+	return s.db.Delete(&db.Attachment{}, id).Error
+}
+
+// DeleteByMessage removes all attachments for a given message.
+func (s *attachmentStoreGorm) DeleteByMessage(messageID uint) error {
+	return s.db.Where("message_id = ?", messageID).Delete(&db.Attachment{}).Error
+}