Glide Lists are a fundamental component in ServiceNow that allow administrators to store and manage multiple values within a single database field. Unlike traditional relational database fields that hold only one value, Glide Lists enable the storage of comma-separated values, making them ideal for…Glide Lists are a fundamental component in ServiceNow that allow administrators to store and manage multiple values within a single database field. Unlike traditional relational database fields that hold only one value, Glide Lists enable the storage of comma-separated values, making them ideal for scenarios where multiple selections are required.
In ServiceNow, Glide Lists are commonly used for fields like 'Watch list' on incident records, where multiple users need to be notified about updates. The field type 'List' in the dictionary stores these values as a string of sys_ids separated by commas, while the platform handles the display and manipulation through the user interface.
From a database administration perspective, Glide Lists utilize a many-to-many relationship concept but store it differently than traditional junction tables. The values are serialized into a single field, which can impact query performance when searching within these fields. Administrators should be mindful of this when designing solutions that require frequent filtering based on list contents.
The GlideList2 API provides client-side JavaScript methods for manipulating list fields, allowing developers to add, remove, or retrieve values programmatically. Server-side manipulation is handled through GlideRecord methods where you can use setValue() and getValue() to manage the comma-separated string.
Key considerations for System Administrators include understanding that Glide Lists have size limitations based on the underlying field length, and that reporting on list fields can be challenging since standard queries may not efficiently search within the concatenated values. Best practices suggest using Glide Lists for relatively small collections of related records.
When configuring list fields, administrators can specify the reference table that defines what type of records can be added to the list. This ensures data integrity by restricting selections to valid records from the designated table, such as limiting a user list field to only accept records from the sys_user table.
Glide Lists in ServiceNow: Complete Guide for CSA Exam
What are Glide Lists?
Glide Lists are a fundamental data type in ServiceNow used to store multiple values in a single field. They function as comma-separated lists of values, typically storing reference values such as sys_ids or user identifiers. The most common example is the Watch list field on incident records, which can contain multiple user references.
Why are Glide Lists Important?
Understanding Glide Lists is crucial for several reasons: - They enable storing multiple related records in a single field - They reduce the need for creating separate many-to-many relationship tables in simple scenarios - They are extensively used throughout the ServiceNow platform for features like watch lists, assignment groups, and approval workflows - Proper manipulation of Glide Lists is essential for scripting and automation tasks
How Glide Lists Work
Glide Lists store data as comma-separated sys_ids internally. When displayed to users, ServiceNow renders these as readable display values. Key characteristics include:
- Storage Format: Values are stored as comma-separated strings (e.g., sys_id1,sys_id2,sys_id3) - Reference Type: Each entry typically references a record in another table - GlideList API: ServiceNow provides the GlideList class for manipulation - Common Methods: add(), remove(), contains(), and toString()
Working with Glide Lists in Scripts
When scripting with Glide Lists, you can use methods like: - getValue() returns the comma-separated string - setValue() accepts comma-separated values - Use split() and join() for array manipulation - The GlideList2 class provides additional functionality for client-side operations
Exam Tips: Answering Questions on Glide Lists
1. Remember the storage format: Questions often test whether you understand that Glide Lists store sys_ids as comma-separated values internally.
2. Know common use cases: Watch lists, group membership, and approval lists are frequently referenced examples. Be familiar with where Glide Lists appear in the base system.
3. Understand field type configuration: Glide Lists are configured as a specific field type in the dictionary. Know that you select 'List' as the type and specify a reference table.
4. Script context matters: Questions may present scenarios asking how to add or remove values. Remember that you work with the field as a comma-separated string and can use JavaScript string/array methods.
5. Distinguish from related lists: Do not confuse Glide Lists (a field type) with Related Lists (UI elements showing related records). This is a common exam trap.
6. Performance considerations: For exam scenarios involving large datasets, recognize that Glide Lists are suitable for smaller collections. Large many-to-many relationships should use junction tables instead.
7. Client vs Server scripting: Know that GlideList2 is used on the client side, while server-side scripts work with the field value as a string or use GlideList methods.
Key Takeaways for the CSA Exam
- Glide Lists store multiple reference values in one field - Data is stored as comma-separated sys_ids - The Watch list field is the classic example - Know the difference between Glide Lists and Related Lists - Understand when to use Glide Lists versus many-to-many tables