Data Tables, Subscriber Keys & Sequences
Use a primary key to update rows and map a safe identity for email sends.
Open interactive lesson and quizWhat you will learn
- Distinguish Data Tables from CRM custom objects
- Configure a unique primary key and send mapping
- Fill and automate sequential values without overwriting data
- Check subscriber identity and consent before activation
An events team imports 1,000 registrants. Each row needs a durable external key, a separate email address and a business-defined subscriber key before a Send Flow.
Lesson 1
Pick the right record structure
CRM custom objects represent business records with owners, lookups, lifecycle rules and related lists. Marketing Data Tables use the existing custom record storage but add a configurable primary key, an email field for Audiences and an optional subscriber key mapping. Choose the structure based on its job. A Data Table without a mapped email can still be filtered and analyzed but does not have a default send destination. Configuration requires both Marketing Data manage and Object configuration permissions.
Lesson 2
Match imports by the primary key
The primary key is a chosen existing text field. Once configured, every table row must have a unique nonblank value. Data Handler uses it to find an existing row when Update duplicates is selected; Object Record API upserts also match the mapped key. The display name is no longer the matching identity. A duplicate key or missing key without a generator stops the write. Review rejected import rows and fix the source. A CRM custom object still keeps its original record behavior.
Lesson 3
Create and fill a safe sequence
Choose any table text field as the sequence target, supply a prefix, a number width and the next number. With xxxxx-, width 5 and next 1, the first value is xxxxx-00001. Select Fill blank values to give existing rows distinct numbers in a deterministic order; nonblank values remain unchanged. New records with a blank target field take the next value. The update and counter move together, and a duplicate generated field value rejects the write. Review existing values before changing a prefix or starting number. Do not generate email addresses this way.
Lesson 4
Separate recipient address from subscriber identity
A mapped Email field supplies the delivery address when a new Audience selects this Data Table. A mapped subscriber key is a separate optional text field; it must be unique within the BU and compatible with the existing subscriber for that email. The subscriber ledger has an immutable internal ID that links send history even if the visible key is changed. An existing different custom key for the same email blocks the mapped send rather than silently replacing identity. Suppression, category preferences and recipient deduplication still apply before delivery. Preview the Audience, review the Send Flow and fix mapping conflicts before activation.
Practice · Prepare an event recipient table
- Create a Data Table with External key (Text), Email address (Email), Subscriber key (Text) and Campaign code (Text).
- In its settings choose External key as primary key, Email address for sends and Subscriber key for identity.
- Configure a sequence on External key with prefix xxxxx-, width 5 and next number 1. Select Fill blank values to populate an existing test batch, then add one new row and check its value.
- Import a correction with Update duplicates and the same External key; verify the original row changes instead of creating another.
- Create a Data Table Audience, check its default email field and eligible count, and review consent and keys before a Send Flow.