Michael P O'Sullivan

US Patent:

20090300069, Dec 3, 2009

Filed:

May 16, 2009

Appl. No.:

12/467274

Inventors:

Michael Patrick O'Sullivan - Blacksburg VA, US

International Classification:

G06F 12/00
G06F 17/30

US Classification:

707200, 707100, 707E1701, 707E17045, 711E12001

Abstract:

A method and system for relational database design that allows records to be flagged as deleted but still retained in the database. Deleted records are not included in table viewing or editing activities. Reversing a deletion flag undeletes the record. Records that reference deleted records in delete-cascade relationships are flagged as deleted. Such dependent records are undeleted if the independent records are undeleted, unless the dependent records were independently flagged as deleted. If an active record is dependent on a record in a delete restrict relationship then the independent record cannot be deleted. If a foreign key references a deleted record in a delete-set-null or delete-set-default relationship then the field evaluates to null or the default value, but if the independent record is undeleted then the field returns to referencing the independent record. Unique indexes are enforced without regard to deleted records.