# Cypher Query for updating a list of nodes **URL:** \ **Category:** Cypher\ **Tags:** apoc, cypher\ **Created:** [October 20, 2020, 12:32pm UTC](https://community.neo4j.com/t/cypher-query-for-updating-a-list-of-nodes/27533 "2020-10-20T12:32:28Z")\ **Posts on this page:** 6\ **Page:** 1
**Author:** ![alishahaan9](https://sea1.discourse-cdn.com/flex021/user_avatar/community.neo4j.com/alishahaan9/32/4376_2.png) [@alishahaan9](https://community.neo4j.com/u/alishahaan9)\ **Post date:** [October 20, 2020, 12:32pm UTC](https://community.neo4j.com/t/cypher-query-for-updating-a-list-of-nodes/27533/1 "2020-10-20T12:32:28Z")
I am having a json array of user detail nodes and I do loop over it and check if a **node** already exists with the specific numeric id property; if it exists then check the 'id' property of the node, if the 'id' is numeric( **isdigit** ) then do nothing but if 'id' is not numeric property then update the ' **id**' property and set it to the ' **numeric\_id**'. ```auto for x in all_json: f_id = x.get("id",'') f_num_id = x.get('numaric_id','') tnode = self.find_user_friend(f_num_id, uid) if tnode is not None: #### Update id to numeric id ##### if tnode['n']['id'].isdigit(): pass else: tnode['n']['id'] = f_num_id tnode['n'].push() ``` **find\_user\_friend** function is ```auto def find_user_friend(self, t_id, u_id): """ To search for target with respective user """ tnode=None query = """ Match (n:Friend {type:"1"}) where n.numaric_id={tid} and n.uid = {uid} return n """ result = self.graph.run(query, parameters={'tid':str(t_id), 'uid':int(u_id)}) if result.forward() > 0: tnode = result.current() ``` The current process takes time as it searches for every individual node then checks and then update the node. I am looking for the optimized solution. I am beginner in neo4j and familiar with **UNWIND** and **FOREACH** in neo4j but can't really made it for now. Here is what I tried. list\_arr = [{id:"amey",numaric\_id:"123"},{id:"12",numaric\_id:"12"},{id:"amiey",numaric\_id:"113"}] ```auto UNWIND """+ l +""" as c Match (n:Friend {numaric_id : c.numaric_id , uid : '1', type:"1"}) SET n.id = numaric_id ``` Help will be appreciated ---
**Author:** ![david\_allen](https://sea1.discourse-cdn.com/flex021/user_avatar/community.neo4j.com/david_allen/32/13090_2.png) [@david\_allen](https://community.neo4j.com/u/david_allen)\ **Post date:** [October 20, 2020, 12:50pm UTC](https://community.neo4j.com/t/cypher-query-for-updating-a-list-of-nodes/27533/2 "2020-10-20T12:50:02Z")
UNWIND is the way to go, but the way you're passing your array to the query isn't going to work. This: ```auto UNWIND """+ l +""" as c ``` Is trying to unwind a string! The thing to do is to submit your python array as a parameter, and then unwind the parameter. Something like this: ```auto query = """ UNWIND $inputArray AS c Match (n:Friend {numaric_id : c.numaric_id , uid : '1', type:"1"}) SET n.id = numaric_id """ self.graph.run(query, parameters={'inputArray': l}) ``` ---
**Author:** ![alishahaan9](https://sea1.discourse-cdn.com/flex021/user_avatar/community.neo4j.com/alishahaan9/32/4376_2.png) [@alishahaan9](https://community.neo4j.com/u/alishahaan9)\ **Post date:** [October 20, 2020, 1:07pm UTC](https://community.neo4j.com/t/cypher-query-for-updating-a-list-of-nodes/27533/3 "2020-10-20T13:07:56Z")
Hi david, Thanks for responding. What if we unwind a string then how can it be handled? Like this: l = '[{id:"amey",numaric\_id:"123"},{id:"12",numaric\_id:"12"},{id:"amiey",numaric\_id:"113"}]' ---
**Author:** ![david\_allen](https://sea1.discourse-cdn.com/flex021/user_avatar/community.neo4j.com/david_allen/32/13090_2.png) [@david\_allen](https://community.neo4j.com/u/david_allen)\ **Post date:** [October 20, 2020, 1:14pm UTC](https://community.neo4j.com/t/cypher-query-for-updating-a-list-of-nodes/27533/4 "2020-10-20T13:14:32Z")
You simply can't unwind a string; unwind only works on lists/arrays. I dunno -- I guess it might work, if it did, a string would unwind to individual characters? Given your array you want to unwind it to individual objects with id/numaric\_id keys and process each of these sequentially. Doing something like this """ + l + """ interpolates the python string representation of the array into an actual string, which is not the same thing. ---
**Author:** ![andrew\_bowman](https://sea1.discourse-cdn.com/flex021/user_avatar/community.neo4j.com/andrew_bowman/32/73_2.png) [@andrew\_bowman](https://community.neo4j.com/u/andrew_bowman)\ **Post date:** [October 23, 2020, 12:10am UTC](https://community.neo4j.com/t/cypher-query-for-updating-a-list-of-nodes/27533/5 "2020-10-23T00:10:03Z")
Looks like this is a JSON string. You would need to first convert this into a structure (a list of maps), then you could UNWIND the list so you have a map on each row. You can use APOC convert functions for this: ```auto WITH '[{id:"amey",numaric_id:"123"},{id:"12",numaric_id:"12"},{id:"amiey",numaric_id:"113"}]' as inputString WITH apoc.convert.fromJsonList(inputString) as list UNWIND list as row RETURN row.numaric_id ``` If the JSON string is the input, then just use apoc.convert.fromJsonList() on the parameter. ---
**Author:** ![david\_allen](https://sea1.discourse-cdn.com/flex021/user_avatar/community.neo4j.com/david_allen/32/13090_2.png) [@david\_allen](https://community.neo4j.com/u/david_allen)\ **Post date:** [October 23, 2020, 10:46am UTC](https://community.neo4j.com/t/cypher-query-for-updating-a-list-of-nodes/27533/6 "2020-10-23T10:46:44Z")
it's not JSON as the keys are lacking quotations around them. It's a python dictionary, which is why I'm thinking submitting it raw as a parameter is the way to go