Set Field

The Set Field node adds a new field or overwrites an existing field on each row using an expression. Use it to compute derived values, inject timestamps, or merge data from other sources.

Configuration

Property	Type	Default	Description
fieldName	string	--	Required. The name of the field to set.
expression	string	--	Required. An expression that computes the field value. The row variable refers to the current row.

Input

Accepts a single object or an array of rows.

Output

Returns the same structure with the new field added to each row. All existing fields are preserved.

Expression Context

Variable	Description
row	The current row being processed
input	Same as row (for single-object input)

Example Configurations

Set a timestamp

fieldName: "created_at"
expression: "now()"

Compute a total

fieldName: "total"
expression: "row.price * row.quantity"

Inject the current user's ID

fieldName: "user_id"
expression: "user_meta('ID')"

Build a full name

fieldName: "full_name"
expression: "row.first_name ~ ' ' ~ row.last_name"

Set a default status

fieldName: "status"
expression: "'pending'"

Conditional value

fieldName: "label"
expression: "row.price > 100 ? 'Premium' : 'Standard'"

Example Use Cases

Add metadata before saving

In a form submission pipeline, add system fields before the Save Row node:

Context --> Set Field (created_at = now()) --> Set Field (user_id = ...) --> Validate --> Save Row

Compute a display field

Table Query --> Set Field (fieldName: "display_price", expression: "'$' ~ number_format(row.price, 2)") --> Result

Enrich rows with computed values

Table Query --> Set Field (fieldName: "age_days", expression: "...") --> Result

TIP

Set Field preserves all existing fields and only adds or overwrites the specified field. To replace the entire row structure, use the Mapping node instead.