Data Mappers17% of the exam
Mapping lists and nested JSON structures
How Data Mapper mappings build the output structure you need: colon paths that rename and reparent nodes, list position indexes, moving a list to another level, turning a list of objects into a list of values, array merging rules, Quick Match and what Preview shows.
Map source and target data structures to achieve expected output structure.
~7 min read · 5 practice questions ·
What the exam expects
- Rename and reparent fields by mapping an input JSON path to a colon-delimited output path.
- Use list position indexes (
|1,|2) to build or reshape short lists, and know which list shapes can't be converted. - Move a list to a different level of the hierarchy, and convert a list of objects of any length into a list of values with a formula.
- Predict how a Transform treats arrays mapped to a single object and several lists mapped to one output list.
- Map with Quick Match (Auto Match, Pair) and read the Preview tab correctly.
Key terms: JSON path (a colon-delimited route to a node, such as Site:Contact:Phone), list position index (|n after a node, selecting the nth list item), list of values (an array of bare values with no keys), Quick Match (the dialog that pairs input and output fields), Auto Match (pairs fields whose names match).
Key facts
Restructure or rename
- Detail
- Map the input path to the desired output path
Path delimiter
- Detail
- A colon separates levels
List position index
- Detail
|1,|2after a node selects an item
Bare-value list
- Detail
- Can't be converted to a keyed list
Change a list's level
- Detail
- Short list with a known number of items only
Objects to values, any length
- Detail
- Formula
ObjectList:Property, map its result path
List cast to a primitive
- Detail
- Only the first element is output
Several lists to one output list
- Detail
- Order not guaranteed; combine with a formula
Auto Match
- Detail
- Matches fields with matching names only
Preview decimals
- Detail
- Trailing zeros removed in the Response panel
Sources for this section (8)
- Transform mappingshelp.salesforce.com (opens in a new tab)
- Use Formulashelp.salesforce.com (opens in a new tab)
- Listshelp.salesforce.com (opens in a new tab)
- List levelhelp.salesforce.com (opens in a new tab)
- List of valueshelp.salesforce.com (opens in a new tab)
- Output Data Typeshelp.salesforce.com (opens in a new tab)
- Configure an Extracthelp.salesforce.com (opens in a new tab)
- Preview and Testhelp.salesforce.com (opens in a new tab)
- Why can't a list like
["Red", "Blue"]be turned back into keyed nodes? - When is moving a list to another level with indexed mappings appropriate?
- Why might two input lists mapped to one output list come back in a different order each run?
- What does a Transform return when a two-record array is mapped to a single-object output?
The questions are free to read. Answers with their sources and self-grading are included with the pack.
Keep reading with the Omnistudio Developer pack
- Core concepts
- Exam traps
- Worked scenario
The pack includes:
- All 46 lessons of the Omnistudio Developer guide, with reading progress
- Interactive decision walks and step-by-step sequence steppers
- Inline practice questions and one-click topic practice (5 questions for this lesson)
- An official source cited for every claim
- An AI tutor that answers from the guide
- Unlimited timed practice exams