fix: batchst reuse_node逻辑完善2

apps/wpm/models.py

@@ -641,10 +641,10 @@ class BatchSt(BaseModel):
             if mio is None and handover is None and mlog is None:
                 raise ParseError("mio or handover or mlog must be provided")
             # 带有来源的批次获取，需检查批次号是否可用
-            if cls.objects.filter(batch=batch).exists():
+            cls_qs = cls.objects.filter(batch=batch)
+            if cls_qs.exists():
                 if reuse_node:
-                    cls = cls.objects.filter(batch=batch)
-                    node:BatchSt = (cls.objects.filter(mio__isnull=False)|cls.objects.filter(
+                    node:BatchSt = (cls_qs.filter(mio__isnull=False)|cls_qs.filter(
                         material_start__isnull=True)).order_by('-version').first()
                     if node is None:
                         raise ParseError(f"{batch}-该批次号因物料不同不可引用")