1. QBE has facilities for modifying the database.

Deletion

1. We simply use D. instead of the P. operator. Whole tuples may be deleted, or only some columns.
2. Delete all of Smith's account records:

3. Delete the branch-city value for the SFU branch:

4. Delete all loans with loan numbers between 1300 and 1500:

5. Delete all accounts at branches located in Burnaby:

Insertion

1. Insertion uses the I. operator.

2. To insert an account tuple for Smith:

3. If values are missing, nulls are inserted.

4. To provide all loan customers in the SFU branch with a $200 savings account:

Updates

1. We can update individual attributes with the U. operator. Fields left blank are not changed.

2. To update the assets of the SFU branch to $10,000,000:

3. To make interest payments of 5% on all balances: