Merge Collections Transformation
Overview
The merge collections transformation creates a new field with all the values in a set of selected multi-valued fields.
Use Cases
This transformation can be used to accomplish the following:
- Producing a set union of students in a certain collection of classes
- Joining two membership lists together
- Combining two lists where duplicate values are significant
Prerequisites
This transformation requires at least one multi-value field.
Contribution
This transformation adds a multi-valued target field containing the concatenated values.

Configuration
The merge collections transformation requires the following by way of configuration:

| Attribute | Description |
|---|---|
| Collections | The list of collections that can be selected. Multiple options can be selected by Ctrl+Clicking. |
| Target Column | The new field to be added containing the concatenated multi-valued values. |
| Members Distinct | Whether the target field will only contain distinct values. |
Change Processing
During the change detection process, a change will be flagged if any of the source fields are updated in the base or relational connector.