We have a data table in Thingworx of usernames and passwords. Using these the user would enter his/her own username and password and it would retrieve that info from the data table in Thingworx to check if its correct.
Is there any way this could be achieved?
Not sure how you are setting this up, but if you are using a Datatable then a service like QueryDataTableEntries can help retrieve the right record based on User name provided, then you can just use a <password> === <savedpassword> in your service.