ServiceNow Expeditions #17 - Connecting Data - Many to Many (m2m) Tables

This episode tackles a common architectural challenge: migrating away from outdated Glide List fields to the platform's best practice—Many-to-Many (M2M) tables.

Join Maik, Ola, and Ivan as they explain why M2M tables are superior for data integrity, querying, and extensibility (like adding roles to a relationship). We provide a step-by-step guide on creating an exempted M2M table via the sys_m2m table to save on custom table counts and cover essential post-creation steps: from setting labels to fixing the infamous "missing edit button" bug. Master the M2M concept and future-proof your data models.

✳ 𝐓𝐀𝐊𝐄𝐀𝐖𝐀𝐘𝐀𝐒 ✳

M2M Necessity: Whenever two tables should relate without restrictions (many-to-many) and you need metadata (like a user's role) or better querying capability, an M2M table is required.

Custom Table Quota: The recommended way to create an M2M table is via the sys_m2m table (Many-to-Many Definitions). This creates an exempted table that does not count against your custom table quota.

Table Name Pattern: For the technical name, it's best practice to use a clear pattern, such as the from_table followed by m2m_ and then the to_table name.

Polishing Work: After creating the M2M definition, you must still open the generated table to handle essential "polishing" work, such as changing labels, configuring form/list views, and setting security.

Missing Edit Button Bug: When changing the related list label, ServiceNow may automatically check the "Omit Edit button" on the list control, which you must manually uncheck to re-enable the slush bucket.

Security (ACLs): Always review the security implications (ACLs) for the M2M table. You might want to remove the "New" button via list control because users should not be creating records in the target table (e.g., a new user) from the M2M form, etc.

✳ 𝐂𝐇𝐀𝐏𝐓𝐄𝐑𝐒 ✳

0:00 - Intro
00:27 - The Problem: Glide Lists vs. Related Lists
02:35 - Conceptual View: How M2M Tables Fix Many-to-Many Relationships
05:05 - Creating an Exempted M2M Table via sys_m2m
10:35 - Adding the M2M Table as a Related List
12:38 - Customizing the Related List UI: Fixing the Missing Edit Button
14:22 - Extensibility: Adding Roles and Duplicating Records for Context
19:12 - Deactivating and Cleaning Up the Old Glide List Field
20:39 - Key Takeaways
23:25 - Outro

✳ 𝐑𝐄𝐅𝐄𝐑𝐄𝐍𝐂𝐄 ✳

SN Utils - https://www.arnoudkooi.com/
ServiceNow Custom Table Guide - https://www.servicenow.com/content/dam/servicenow-assets/public/en-us/doc-type/legal/custom-table-guide.pdf?
Things to do with Many to Many tables in Servicenow by Chuck Tomasi - https://youtu.be/K4Dd1weTET0?si=wyJNcLYJCblWQnOu

✳ **𝐃𝐈𝐒𝐂𝐋𝐀𝐈𝐌𝐄𝐑** ✳
This video is for educational purposes only. Information is provided as-is without any warranty of accuracy or completeness. Use of this information is at your own risk. We do not hold rights to third-party materials used under fair use for educational objectives. We are not liable for any loss or damage arising from your actions based on the content of this video.

Видео ServiceNow Expeditions #17 - Connecting Data - Many to Many (m2m) Tables канала ServiceNow Expeditions