Explain with examples how the UPDATE and DELETE commands work with the WHERE clause.

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The UPDATE command modifies existing records, and the WHERE clause decides which record(s) are changed. Example: UPDATE Student SET City='Bhaktapur' WHERE Name='Sita'; — this changes only Sita's city, leaving other records unchanged. The DELETE command removes records, and WHERE decides which ones are removed. Example: DELETE FROM Employee WHERE Name='Hari'; — this removes only Hari's record. In both cases, omitting the WHERE clause would affect all records in the table.