Required fields must have a non-null value. This rule affects the create and update calls:
- In a create call, the system automatically populates the data
for certain required fields (such as system fields and the object
ID fields). Similarly, if a required field has a default value (its defaultedOnCreate attribute is set to true, as described in Field in a describe result, then the system implicitly assigns a
value for this field when the object is created, even if a value for
this field is not explicitly passed in on the create call. For all
other required fields, such as ID fields that are analogous to foreign
keys in SQL, a client application must explicitly assign a value when
the object is created (it cannot be null).
- In updates, a required field cannot be set to null, and many required fields can’t
Any field not specified as required in the object description is
optional, that is, it can be null when updated or created.
Some required fields for some objects require special handling.