get history of changes for an incident field (Assigned To)

[Mario Landa]

Hello guys,

I need the history of changes for the Assigned to Field, I am working in the sandbox and enabling auditing for the incident table as suggested here:
https://docs.servicenow.com/bundle/geneva-servicenow-platform/page/administer/security/task/t_EnableAuditingForATable.html

Yields nothing when I make the API call. Querying sys_dictionary , sys_audit, sys_history_line or sys_history does not work either. I dont know what to do, im using python. Here is one example, the requests that come back are empty or invalid, how else can I do this? Is there a way to get the " Field changes " table? thank you!

# Set the request parameters
    url = env + 'api/now/table/sys_audit/' + sys_id
    
    # Set proper headers
    headers = {"Content-Type":"application/json","Accept":"application/json"}
    
    # Do the HTTP request
    response = requests.get(url, auth=(user, pwd), headers=headers ,data="{\"fieldname\":\"assigned_to\"}")
    
    # Check for HTTP codes other than 200
    if response.status_code != 200: 
        print('Status:', response.status_code, 'Headers:', response.headers, 'Error Response:',response.json())
        exit()
    
    # Decode the JSON response into a dictionary and use the data
    data = response.json()
    return data

[Mario Landa]

this does not work unfortunately, I dont know what else to do.

[SanjivMeher]

Can you remove the below marked in bold and try

response = requests.get(url, auth=(user, pwd), headers=headers)

[Steve Socha]

Hi Mario,

I believe you're looking for the sys_history_line, but you'll have to do some dot-chasing to access the correct attribute. Try performing a table query with sysparm_query=set.id=${incident_id}

Using the Table API, this would come out to a GET call to

https://INSTANCE_NAME.service-now.com/api/now/table/sys_history_line?sysparm_query=set.id=05f7875cdb982b00f2e4d2984b961966

Possibly with an addition on the query to only look for assigned_to entries, which could be arranged by appending ^field=assigned_to to the end of the URL

[Steve Socha · Accepted solution]

Hi Mario,

Could you set my response to correct if this query retrieved the correct details for you?

Cheers,

Steve

[Mario Landa]

The response returns a result object and then you can check if the field modified is "assigned_to" and parse it like this:

for ticket in getServiceAssignedToHistory(sys_id goes here)["result"]:
    if(ticket["field"] == 'assigned_to'):
        print("old user :")
        print(ticket["old"])
        print("new user")
        print(ticket["new"])

Thank you very much! It works now!