MySQL Problem 4: You are required to execute these two relational algebraic oper

Question

MySQL

Problem 4:

You are required to execute these two relational algebraic operations:

(a) STUDENT.SNO intersection RESULT.SCORE

(b) STUDENT.SNO union RESULT.SCORE

Express both in SQL and evaluate.

Do you get an error?

If you do, at what stage of processing do you think the system detects the error?

For example, at the stage of compiling the query expression or at the stage of evaluating the query expression?

Any observation you would like to offer for this experiment?

Here is the table schema

CNAME 21 Computer Science 17 Chemist 15 PhysicS 12 Mathematics l 13 Mathematics III RESULT CNO CNO STUDENT SNO SNAME ADDRESS SEX SCORE 31 L. Gatlin Holcomb F 11 N. Park Whitney M 22 S. Conner: Holcomb F 24 D. Davissc E. Quad M 19 1. Blake Holcomb M 4 T. Smith Cambridg F SNO 2 2 2 2 2 2 31 14 2 63 4 Histo 3 Geography 2 Biology 72 1 N. J. Sloan Whitney F 14 D. E. Knutl Whitney M 6 J. Brown Whitney 2 M. Robert Cambridg M 14 33 U. Smith Cambridg F 14 37 2 13 13 13 13 97 72 11 NULL 14 61 52 63

Explanation / Answer

If you have any doubts, please give me comment...

a)

SELECT STUDENT.SNO

FROM STUDENT

INTERSECT

SELECT RESULT.SCORE

FROM RESULT;

b)

SELECT STUDENT.SNO

FROM STUDENT

UNION

SELECT RESULT.SCORE

FROM RESULT;

We didn't get any error, because they both have common domain.

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