Preventing Duplicate Locations

Overview

This document outlines a solution to enforce data integrity on the Location (cmn_location) table by preventing the creation of duplicate records.

The logic ensures that no two locations can share the same Name and Parent combination. This is a critical validation because ServiceNow’s full_name field (e.g., USA / California / San Diego) is calculated after the record is inserted, making standard uniqueness checks on that field unreliable during the initial save.

Problem Statement

In many ServiceNow environments, users accidentally create duplicate location records because:

• The full_name field is not yet populated during a before Business Rule.
• Global organizations often have multiple rooms or sub-sites with the same short name (e.g., “Conference Room A”), but they reside under different parent locations.
• Standard “Unique” field indexes on the name column alone are too restrictive, while checks on full_name fail to trigger accurately on new inserts.

The goal is to provide real time feedback to the user and abort the database action if a duplicate hierarchy is detected.

Why Validate Name + Parent (Not Full Name)?

The full_name field is a “Calculated” field or populated via an After Business Rule process. If you run a script before the insert, current.full_name is effectively empty. By validating the Name and Parent fields specifically, we bypass this limitation and check the data that will eventually form the full name, ensuring integrity before the record ever hits the database. Additionally the us of the ‘unique’ index on the full_name field is not possible due to the system creating the location record and then calculating the full_name after the fact, which would allow duplicates and then throw an error after the fact, which is not ideal for user experience nor data integrity.

Business Rule: Prevent Duplicate Location

Table: Location (cmn_location)
When: Before (Insert and Update)

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(function executeRule(current, previous /*null when async*/) {

    // Initialize GlideRecord to check for existing records with the same naming structure
    var locGR = new GlideRecord('cmn_location');
    locGR.addQuery('name', current.name);
    
    // Validating against the parent sys_id
    locGR.addQuery('parent', current.parent); 
    
    // Ensure we aren't flagging the record we are currently updating
    locGR.addQuery('sys_id', '!=', current.getUniqueValue());
    
    locGR.query();

    if (locGR.next()) {
        // Construct a helpful message for the end user
        vvar parentDisplay = current.parent.getDisplayValue() || "No Parent";
        var errorMsg = gs.getMessage(
            "A location named '{0}' already exists under the parent '{1}'. Please use a unique combination.", 
            [current.name.toString(), parentDisplay]
        );
        
        gs.addErrorMessage(errorMsg);
        
        // Stop the record from being created or updated
        current.setAbortAction(true);
    }

})(current, previous);