EntityHistory

Represents historical information about an object’s changed field values. This object is only available to users with the “View All Data” permission.

Supported Calls

Field	Field Type	Field Properties	Description
FieldName	picklist	Filter Restricted picklist	ID of the standard or custom field. For information on IDs, see ID Field Type.
IsDeleted	boolean	Defaulted on create Filter	Indicates whether the object has been moved to the Recycle Bin (`true`) or not (`false`). Label is Deleted.
NewValue	anyType	Nillable	New value of the modified field.
OldValue	anyType	Nillable	Previous value of the modified field.
ParentId	reference	Filter	ID of the object that contains the field.
ParentSobjectType	picklist	Filter Restricted picklist	The kind of object that contains the field.

In API version 7.0 and later, this object works with Case, Contract, and Solution objects:

This object is always read-only in the online application.
When a field is modified, this object records both the old and new field values.
There are exceptions to this behavior for certain fields such as long text areas and multi-select picklists. These fields appear in this object to indicate that the field was changed, but the old and new values are not recorded.
Two rows are added to this object when foreign key fields change. One row contains the foreign key object names that display in the online application. For example, “Jane Doe” is recorded as the name of a contact. The other row contains the actual foreign key ID that is only returned to and visible from the API.
Up to a total of twenty fields (standard or custom) can be tracked for a given object.
In the online application, you can specify which fields are tracked or not tracked at any time. See the Salesforce.com online help for more information.
As soon as tracking is turned on for a field, all changes to its value are recorded in the database.
Turning off tracking for a field stops further changes from being recorded, but the history data is not deleted.
Be advised that deleting a custom field also permanently deletes the history data for that custom field.