The UPDATE statement is used to update existing data in a table. The WHERE clause in the UPDATE statement specifies which record/records should be updated. If you omit the WHERE clause, all records will be updated.
UPDATE employees SET emp_name = 'Sarah' WHERE emp_id = 3;
UPDATE employees SET salary = 20000;
UPDATE employees SET salary = 6000, dept_id = 2 WHERE emp_id = 5;