CS 377 Database Systems Relational Calculus and SQL

RESTRICTED: only the attribute table_name.attr_name is dropped - however, if the attribute table_name.attr_name is a part of a foreign key in some other relation, it cannot be dropped. E.g. You cannot drop employee.ssn because it is used as a foreign key in dependent department 29, , etc CASCADE: the attribute table_name.attr_name is dropped ... ................
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