Page 1 of 1
Below are constraints expressed first in relational algebra, then in SQL. Indicate which ones match. 0 Assuming that S.i
Posted: Tue Jul 12, 2022 8:22 am
by answerhappygod
- Below Are Constraints Expressed First In Relational Algebra Then In Sql Indicate Which Ones Match 0 Assuming That S I 1 (51.85 KiB) Viewed 27 times
Below are constraints expressed first in relational algebra, then in SQL. Indicate which ones match. 0 Assuming that S.id is already a primary key: Psı(S) S1.id<>S2.id/S1.x=S2.x PS2(S) = Ø ALTER TABLE `S MODIFY x INT UNIQUE; x>1000(R) = Ø ALTER TABLE R MODIFY `x` INT CHECK(x ≤ 1000); study_year>age (Student) = Ø ALTER TABLE `Student` MODIFY study_year` INT CHECK(`study_year` <= age`); Tz (R) C Ty(S) ALTER TABLE RADD CONSTRAINT `fk_rx_sy` FOREIGN KEY(`x`) REFERENCES `S` (`y`);