Dec 07, 2017 10:00 AM|Billy Liu|LINK
Are you using Oracle right?
It seems Oracle does not allow joining tables in an UPDATE statement. You need to rewrite your statement with a co-related sub-select.
SET T_CHARACTERISTICS.PROCESS = (select T_DOC.PROCESS
where T_CHARACTERISTICS.ID = T_DOC.ID)
You could refer to the link below for more information: