What is coalesce checkbox and How it execute

[kpathak1803]

What is coalesce checkbox and How it execute? 

Please do let me know.
Thank you!

[G Ponsekar · Accepted solution]

Hi @kpathak1803 ,

Coalesce is a feature in ServiceNow that determines if a row in a staging table matches a record in a target table. It can be used to prevent duplicate data and update existing records instead of creating new ones.

Coalesce is like unique key, if match found then update else create a new record

If I could help you with your Query then, please hit the Thumb Icon and mark as Correct !!

Thanks, GP

[Chaitanya ILCR]

HI @kpathak1803 ,

refer this 

https://developer.servicenow.com/dev.do#!/learn/learning-plans/xanadu/servicenow_administrator/app_s...

explained with a good example

https://www.servicenow.com/community/itsm-forum/what-is-coalesce-explain-with-example/td-p/2341075

https://www.youtube.com/watch?v=EY8HLx5I580

Please mark my answer as helpful/correct if it resolves your query.

Regards,
Chaitanya

[shyamkumars]

@kpathak1803  - 

Coalesce is commonly used with Transform maps in ServiceNow. It is used to set a field as unique , this will avoid Duplication during the Import

For more context refer to following , this below link response helps you to understand more on the Topic

https://developer.servicenow.com/dev.do#!/learn/learning-plans/xanadu/servicenow_administrator/app_s...

https://www.servicenow.com/community/itsm-forum/what-is-coalesce-explain-with-example/td-p/2341075

[Dr Atul G- LNG]

Hi @kpathak1803 

https://youtu.be/f5DCq8GJ3pQ 

https://youtu.be/vKIQ1IZDP10

My tutorial will be helpful here.

[GlideFather]

Hi @kpathak1803,

you got definition in parallel answers or you can simply google it but let me give you a real use case:

For the user management a client has LDAP (user database with all their details - name, email, location, position, department, whatever) and ServiceNow for their ITSM.

LDAP and ServiceNow are two different systems, so when you want to keep the data 1:1 in both sides, you need to integrate and sync between them. And because user ID in LDAP is different than user ID in ServiceNow as well as sys ids, so for that there is a coalesce.

When LDAP is sending data towards ServiceNow there might be two people with the same name (John Doe) to be sure that the data are not mixed, there is a coalesce field that will determine whether it is the same record based on same unique identifier (usually email).

• LDAP sending data to ServiceNow - check for the email and email in LDAP is equal to email in ServiceNow thus the rest of the data are used to update, if there is no change, nothing happens.
• LDAP sending data to ServiceNow - check for the email and this email doesn 't exist in ServiceNow, so a new user will be created.

Let me know if this simplified example makes sense to you

[_Tushar Soni]

Hi @kpathak1803 ,

What is the Coalesce Checkbox in ServiceNow?

-- The Coalesce checkbox is used in Transform Maps when importing data into ServiceNow. It helps the system decide whether to update an existing record or create a new one.

How Does It Work?
When you mark a field as Coalesce, ServiceNow checks if a record in the target table already exists with the same value in that field:

✅If a match is found → the existing record is updated.
❌If no match is found → a new record is created.
This helps avoid duplicate records and keeps your data clean.

Example:
Let’s say you’re importing user data and you mark the Email field as coalesce:

If a user with that email already exists → their record will be updated.
If not → a new user record will be created.

If you found my response helpful, please consider marking it as "Helpful" or "Accept Solution." Thank you!