Flow Cross Object Updates

Flow Cross Object Updates

Activate when a flow must read or write a record other than the one that triggered it. Getting the pattern right avoids SOQL-inside-loop disasters and preserves bulk behavior when 200 records arrive at once.

Before Starting

• Identify the relationship direction. Child→parent (lookup traversal) and parent→child (Get Records for related list) behave differently.
• Check bulk context. Record-triggered flows run with up to 200 records per batch — every Get/Update inside a loop multiplies by 200.
• Prefer formulas for read-only parent fields. $Record.Account.Name is free; a Get Records call is not.

Core Concepts

Child → Parent read: dot-notation traversal

In a Contact-triggered flow, {!$Record.Account.Industry} resolves the lookup in memory — no SOQL. Traverse up to 5 levels.

Child → Parent write: single Update Records

Update Records:
  Object: Account
  Filter: Id = {!$Record.AccountId}
  Fields to set: Last_Contact_Date__c = {!$Record.CreatedDate}

One DML per flow execution, regardless of batch size — Flow bulkifies automatically as long as the Update is outside a loop.

Parent → Child: Get Records then Update Records

Get Records:
  Object: Contact
  Filter: AccountId = {!$Record.Id}
  Store: All records in collection `contacts`

Loop contacts:
  Assignment: each.Mailing_City__c = {!$Record.BillingCity}
  Add to collection: contactsToUpdate

Update Records (outside loop):
  Input collection: contactsToUpdate

The Update Records is OUTSIDE the loop — this is the single most important bulkification rule.

Rollup-style aggregation

Salesforce has Rollup Summary only on master-detail. For lookups, use:

• CollectionProcessor (Count / Sum of a number collection) → single Update on parent
• Or Declarative Lookup Rollup Summaries (DLRS) — admin-friendly community app

Common Patterns

Pattern: "Last Activity" parent stamp

Record-triggered on Task create → Update Records on WhatId parent setting Last_Task_Date__c = {!$Record.CreatedDate}. One DML, fully bulk-safe.

Pattern: Cascade status to children

Parent Account Status__c changes → Get Records (Contacts where AccountId = parent) → loop assign Status__c → Update outside loop.

Pattern: Guard against recursion

Child → Parent update can retrigger a parent-triggered flow. Use an entry condition on the parent flow (ISCHANGED(relevant field)), or guard with a transient boolean custom setting.

Decision Guidance

Recommended Workflow

1. Map the relationship direction and record volume expected.
2. Prefer dot-notation traversal for reads — avoid a Get Records when a formula suffices.
3. For writes, always keep Update Records OUTSIDE any Loop element.
4. Set entry conditions to prevent unneeded runs (ISCHANGED / ISNEW).
5. Add a Fault path on every Get/Update → Screen or custom error.
6. Test with 1, 2, and 200-record batches in a sandbox.
7. Verify SOQL/DML counts via Debug Logs — should be constant, not scaling.

Review Checklist

• No Update/Create Records inside a Loop
• Dot-notation used where a Get Records is unneeded
• Entry conditions prevent unnecessary execution
• Fault paths present on every data element
• Bulk test (200 records) executed in sandbox
• SOQL and DML query counts verified constant

Salesforce-Specific Gotchas

1. Update Records inside Loop — silent SOQL-101 killer when a batch arrives. No warning at design time; shows up only under load.
2. Dot-notation returns null if intermediate lookup is empty — always null-check: IF(ISBLANK({!$Record.AccountId}), ..., {!$Record.Account.Name}).
3. Recursion between parent-triggered and child-triggered flows — flow runs are not re-entrant by default, but cross-object updates can chain-trigger other flows. Monitor the flow execution stack in the debug log.
4. Record-triggered flows on a child can't see parent field values that were just set by a before-trigger on the parent in the same transaction — order-of-execution still applies.
5. Scheduled paths lose context of original record — if you rely on $Record in a scheduled path, pick up a fresh copy with Get Records.

Output Artifacts

Related Skills

• flow/flow-best-practices — naming, fault paths, documentation
• flow/flow-bulk-testing — verifying 200-record safety
• apex/apex-trigger-handler-pattern — when to switch from Flow to Apex