diff --git a/mupifDB/models.py b/mupifDB/models.py
index 9703461..64cc6e9 100644
--- a/mupifDB/models.py
+++ b/mupifDB/models.py
@@ -41,7 +41,7 @@ class DbRef_Model(StrictBase):
 class TEMP_DbLookup_Model(StrictBase):
     where: str
     attrs: List[str]
-    values: List[str]
+    values: List[str|int]
 
 class MongoObjBase_Model(StrictBase):
     dbID: Optional[DatabaseID]=Field(None,alias='_id') # type: ignore[arg-type]
@@ -53,7 +53,7 @@ def model_dump_db(self):
         ret=self.model_dump(mode='json')
         if '_id' in ret and ret['_id'] is None: del ret['_id']
         return ret
-    def TEMP_getChildren(self) -> List[DbRef_Model]: return []
+    def TEMP_getChildren(self) -> List[Tuple[str,DbRef_Model]]: return []
     def TEMP_getLookupChildren(self) -> List[TEMP_DbLookup_Model]: return []
 
 import abc
@@ -148,8 +148,8 @@ class Link_Model(StrictBase):
     FileID: Optional[str]=None
     Compulsory: Optional[bool]=False # deema: allow None
     Object: dict[str,Any]
-    def TEMP_getChildren(self) -> List[DbRef_Model]:
-        return [DbRef_Model(where=where,id=id) for where,id in [('fs.files',self.FileID)] if id is not None and id!='']
+    def TEMP_getChildren(self) -> List[Tuple[str,DbRef_Model]]:
+        return [('FileID',DbRef_Model(where=where,id=id)) for where,id in [('fs.files',self.FileID)] if id is not None and id!='']
 
 class IODataRecord_Model(MongoObj_Model):
     DataSet: List[IODataRecordItem_Model]=[]
@@ -188,8 +188,7 @@ class Output_Model(InputOutputBase_Model):
     EDMMapping: List[EDMMapping_Model]=[]
     Version: int=1
 
-    # TODO: WorkflowID==self.wid and WorkflowVersion==self.Version
-    def TEMP_getLookupChildren(self) -> List[TEMP_DbLookup_Model]: return [TEMP_DbLookup_Model(where='WorkflowExecutions',attrs=['WorkflowID'],values=[self.wid])]
+    def TEMP_getLookupChildren(self) -> List[TEMP_DbLookup_Model]: return [TEMP_DbLookup_Model(where='WorkflowExecutions',attrs=['WorkflowID','WorkflowVersion'],values=[self.wid,self.Version])]
 
 
 class WorkflowExecution_Model(MongoObj_Model):
@@ -213,8 +212,8 @@ class WorkflowExecution_Model(MongoObj_Model):
     Inputs: str
     Outputs: str
 
-    def TEMP_getChildren(self) -> List[DbRef_Model]:
-        return [DbRef_Model(where=where,id=id) for where,id in [('IOData',self.Inputs),('IOData',self.Outputs),('fs.files',self.ExecutionLog)] if id is not None and id!='']
+    def TEMP_getChildren(self) -> List[Tuple[str,DbRef_Model]]:
+        return [(attr,DbRef_Model(where=where,id=id)) for where,id,attr in [('IOData',self.Inputs,'Inputs'),('IOData',self.Outputs,'Outputs'),('fs.files',self.ExecutionLog,'ExecutionLog')] if id is not None and id!='']
 
 
 
diff --git a/tools/database-add-parents.py b/tools/database-add-parents.py
index 5a3bf1b..a32e3a0 100644
--- a/tools/database-add-parents.py
+++ b/tools/database-add-parents.py
@@ -1,8 +1,9 @@
 
-dbPort=27001
+dbPort=27017
 
 from pymongo import MongoClient
 import pymongo
+import pymongo.errors
 from bson import ObjectId
 import bson, bson.objectid
 from rich import print_json
@@ -105,7 +106,7 @@ def set_attr_null(dbColl,obj,attr):
         progress.update(doc_task,description=' ↳[cyan]…',start=False,visible=False)
         progress.update(chi_task,description='  ↳[yellow]…',start=False,visible=False)
 
-        client = MongoClient(f'mongodb://localhost:27017')
+        client = MongoClient(f'mongodb://localhost:{dbPort}')
         db = client.MuPIF
         progress.reset(col_task,start=True)
         progress.update(col_task,description='↳[green]…',total=len(coll2model),completed=0,visible=True)
@@ -125,10 +126,11 @@ def set_attr_null(dbColl,obj,attr):
                 try:
                     obj=Model.model_validate(rec)
                     thisRef=models.DbRef_Model(where=coll,id=obj.dbID)
-                    for i,cref in enumerate(obj.TEMP_getChildren()):
+                    for i,(attr,cref) in enumerate(obj.TEMP_getChildren()):
                             child=resolve_DbRef(db,cref)
                             if child is None:
-                                log.error(f'Unresolvable child {cref=} (setting to null not yet implemented)')
+                                log.error(f'Unresolvable child {cref=}; setting {attr=} to null!')
+                                set_attr_null(dbColl,obj,attr)
                                 print_mongo(rec)
                                 continue
                             if child.parent is None: