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hw2Sol - Fall 2006 CS143 3.1 Answer(a we count the owners...

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Fall 2006 CS143 HW 2 Solution 3.1 Answer: (a) we count the owners not the accidents ... SELECT count(distinct O.driver_id) FROM participated as P, accident as A, owns as O WHERE A.date >='1989-01-01' AND A.date < '1990-01-01' AND P.report_number=A.report_number AND P.car=O.license (b) add a new accident: first the report and then the participated record referring to the report. All the rest is in place. INSERT INTO accident value (8872, 2006-08-14, `Santa Monica`) INSERT INTO participated value (0023,45678, 8872, 956) (c) Delete the Mazda of John Smith DELETE FROM owns WHERE driver_id in (SELECT driver_id FROM person WHERE name='John Smith') DELETE FROM car WHERE model= `mazda` AND license IN ( SELECT license FROM OWNS as O, person as P WHERE O.driver_id=P.driver_id AND P.name= `John Smith' ) 3.9 Consider the employee database of Figure 3.12, where the primary keys are underlined. Give an expression in SQL for each of the following queries. a. Find the names of all employees who work for First Bank Corporation.
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