Change Data Capture Developer Guide

Change Data Capture
Keep Your External Data Current with Change Data Capture
Change Event Message Structure
Subscribe to Change Events
Security Considerations
Change Event Considerations
Standard Object Notes
Change Events for Fields
Sending Data Differences for Fields of Updated Records
Change Events for Custom Field Type Conversions
Conversions That Generate a Change Event
Conversions That Generate a Gap Event
Conversions That Don’t Generate Events
Other Types of Change Events: Gap and Overflow Events
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Conversions That Generate a Change Event

When converting a custom field type to another type that is not compatible, field data is lost and is set to null in records corresponding to the object. One change event is generated for all the affected records, and the event message contains no record fields.

Examples of incompatible field changes are:

  • Changing a Date or Date/Time field to any other field type, and vice versa
  • Changing a Checkbox field to any other field type
  • Changing a Picklist (Multi-Select) field to any other field type

For a complete list of conversions that result in data loss, see Notes on Changing Custom Field Types.

Because a field type conversion can affect many records, the recordIds header field value in the event message contains a wildcard value instead of a record ID array. The value starts with the three-character object ID prefix, followed by the wildcard character *. For example, if you make an incompatible field type change for an Account custom field, the recordIds field looks similar to the following.

1"ChangeEventHeader": {
2        "entityName": "Account",
3        "recordIds": [
4          "001*"
5        ],
6        ...
7}