feat: 限制用户单日提问次数

service/plant/ai_chat_history_service.go

@@ -46,3 +46,12 @@ func (s *AiChatHistoryService) DeleteHistory(userId, id string) error {
 func (s *AiChatHistoryService) ClearHistory(userId string) error {
 	return global.DB.Where("user_id = ?", userId).Delete(&plantModel.AiChatHistory{}).Error
 }
+
+// GetTodayCount 获取用户今日问答数量
+func (s *AiChatHistoryService) GetTodayCount(userId string) (int64, error) {
+	var count int64
+	err := global.DB.Model(&plantModel.AiChatHistory{}).
+		Where("user_id = ? AND DATE(created_at) = CURDATE()", userId).
+		Count(&count).Error
+	return count, err
+}