SqlContentEntityStorage tries to update identity/serial values by default

Problem/Motivation

SqlContentEntityStorage::mapToStorageRecord sends update statements that includes IDENTITY fields that need to be updated, such as: UPDATE xxx SET nid = 1, property0 = :value0 WHERE nid = 1;. This is not supported in SQL Server because although there is no actual update happening it is explicitly telling the database engine that you wish to perform an update.

Question: Is it correct to allow UPDATE statements that change (even if new value is same as previous) IDENTITY values?

IDENTITY column values are immutable.

Proposed resolution

Remaining tasks

User interface changes

API changes

Original report by david_garcia