避免没有数据的情况

application/third_party/train/models/BIZ_train_model.php

@@ -59,15 +59,21 @@ class BIZ_train_model extends CI_Model {
 				AND	
 					tpc_to_station = '$tpc_to_station'";
 		$query = $this->INFO->query($sql);
-		$cache_time = strtotime($query->row()->tpc_datetime);
-		$now_time = time();
-		$differ_time = ($now_time - $cache_time) / 86400;
-		if($differ_time >= 7){
-			$this->delete_traincache($tpc_from_station,$tpc_to_station);
-			return null;
+		
+		if($query->row()){
+			$cache_time = strtotime($query->row()->tpc_datetime);
+			$now_time = time();
+			$differ_time = ($now_time - $cache_time) / 86400;
+			if($differ_time >= 7){
+				$this->delete_traincache($tpc_from_station,$tpc_to_station);
+				return null;
+			}else{
+				return $query->row();
+			}
 		}else{
-			return $query->row();
+			return null;
 		}
+		
 	}
 	
 	//删除缓存操作