ExternalSystemIdentifier

String (50)

On Insert: Yes (if ProjectTaskUid is not supplied)

On Update: Yes (if ProjectTaskUid is not supplied)One of ExternalSystemIdentifier or ProjectTaskUid is required

The external system identifier is a unique identifier for a project task(may be null, but once set can only be updated to a different, non-null value).

ESI-123

ProjectTaskId

Int32On Insert: No

On Update: No

The project task Id is a unique identifier for a project task. For internal use only.

ProjectTaskUid

Int64

On Insert: Yes (if ExternalSystemIdentifier is not supplied)

On Update: Yes (if ExternalSystemIdentifier is not supplied)See ExternalSystemIdentifier

A unique and immutable identifier for a project task.

1152921504608637358