HP Integrity NonStop J-Series - Manual (Page 187)

USING AN ENABLE APPLICATION
Undoing a DELETE Operation
Undoing a DELETE Operation
To undo a DELETE operation, the application must insert the
deleted record (or records). The application can insert the
deleted record if you have not requested another delete, insert,
update, or read operation since you requested the delete
operation you want to reverse and another application has not
inserted the deleted record.
You can undo a DELETE operation even if your application does not
support insert operations.
Undoing an UPDATE Operation
To undo an UPDATE operation, the application must replace the old
record (or records). The application can replace the old record
if the following is true:
• You have not requested another DELETE, INSERT, READ, or UPDATE
operation since you requested the update operation you want to
reverse.
• Another application has not modified the updated record.
You can undo an UPDATE operation even if you changed the primary
key.
Undoing an INSERT Operation
To undo an INSERT operation, the application must delete the
record (or records) you inserted. The application can reverse
the insert operation if the following is true:
• You have not requested another DELETE, INSERT, READ, or UPDATE
operation since you requested the INSERT operation you want to
reverse.
• Another application has not changed or deleted the inserted
record.
• You did not insert the record (or records) in an
entry-sequenced or unstructured file. The computer system
will not allow the application to delete a record from either
an entry-sequenced or an unstructured file.
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