When executing an update query with multiple tables, all tables are currently required to be writeable.

Please allow us to use read-only tables and queries as a source of data for update queries, e.g.

UPDATE MyWritableTable rw
INNER JOIN MyReadOnlyTable ro ON ro.ID = rw.ID
SET rw.Field1 = ro.Field1

Since there are no write actions to MyReadOnlyTable, this query should not require it to be writable, but it does.

The current behaviour is a common source of misunderstanding (I often see questions about it on Stack Overflow), and limits the ability to update/merge in data from read-only data sources.