限购数量错误

app/Api/Controllers/DrugController.php

@@ -183,7 +183,7 @@ public function drugLimit(Request $request)
             }
             $buyedCount = $drugCounts[$drug['drug_id']] ?? 0; // 历史已购买数量
             $canBuyCount = $drug['limit_num'] - $buyedCount; // 普通药品剩余可购买数量
-            if ($canBuyCount <= 0) {
+            if ($canBuyCount < $drug['num']) {
                 $errMsg = '药品['.$drugModel->name.']剩余购买数量不足~';
 
                 return $this->failed($errMsg, ['add_status' => false]);