Force.com database contains a number of read-only system fields automatically associated with each object. For each record in the database, Force.com automatically assigns an identity field (called ID) and manages the identity data. The ID is a case-sensitive 15 character string that is used to uniquely identify the record throughout the platform.
Read Only System Fields in Salesforce.com
To view a record in the salesforce.com UI, simply append the record ID to your salesforce.com domain. For instance, when you enter https://na1.salesforce.com/0014000000Hg6pL, Force.com will fetch the record from the database, along with its associated metadata, and display the record using the automatically generated UI based upon your security settings.
Each record is also required to have a special “name” field. This can either be an auto-number field or a human-readable identifier for the record to distinguish one record from one another. When Force.com generates a user interface, you’ll see that the value for the name field is always displayed as a link to the detail page of the record itself. Other read-only, system fields include.
- CreatedDate – the date and time when the record was created.
- CreatedById – the ID of the User that created the record.
- LastModifiedById – the ID of the User that last modified the record.
- LastModifiedDate – the date and time when the record was last modified by a User.
- SystemModStamp – the date and time when the object was last modified by a User or system process (e.g., trigger, web service).
System fields are read-only. However, this can pose a problem when trying to import data. You may want to import created dates or created by for these new records. You can contact salesforce.com support and ask them to enable “Create Audit Fields”. This will allow you to import some read-only fields for most standard and all custom objects using the Data Loader.