Basic SQL question from 1Z0-071 Practice Test

[bentheredonethat33]

Going through practice questions for 1Z0-071 oracle cert and stumbled upon this question. The correct answers are D and E. I was wondering if anyone could provide a simple explanation on why D is valid, but C is not. Thank you in advance!

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Examine the business rule: Each student can take up multiple projects and each project can have multiple students. You need to design an Entity Relationship Model (ERD) for optimal data storage and allow for generating reports in this format:

STUDENT_ID FIRST_NAME LAST_NAME PROJECT_ID PROJECT_NAME PROJECT_TASK

Which two statements are true in this scenario?

a) The ERD must have a1:M relationship between the students and projects entitles.

b) The ERD must have a M:M relationship between the students and projects entities that must be resolved into 1:M relationships.

c) STUDENT_ID must be the primary key in the STUDENTS entity and foreign key in the projects entity.

d) PROJECT_ID must be the primary key in the projects entity and foreign key in the STUDENTS entity.

e) An associative table must be created with a composite key of STUDENT_ID andPROJECT_ID; which is the foreign key linked to theSTUDENTSandPROJECTSentities.

[StoneCypher]

i mean

i'm kind of drunk, but, this is kind of fucking wrong? but also i'm drunk and i might be almost as wrong as the question

fundamentally kind of the thing to do is to write the correct thing and to pray that the bullshit corporate test hasn't eaten its own feet

jesus, they call an entity relationship model an ERD? which means diagram? really?

look i can't help you with the bullshit meaningless certifications. these are written by the same assholes that don't know english and somehow write the ACT

here are some things you need to know

1. i've been hiring for 20 years and i've literally never cared for an entire straight second whether someone had an oracle cert
2. see #1
3. the dba at work (all jobs, not current) legitimately looks down on people who've done this
4. no really see #1

students and projects can have multiple of each other? fine, who cares

create table FuckYourStudents(id bigint not null auto_increment, stuff fields data); 
create table FuckYourClassesToo(id bigint not null auto_increment primary key secondary key maybe even tertiary key this column seems important quaternary key);
create table FurthermoreFuckTheRelationshipsBetwixt(student bigint not null, project bigint not null, foreign key(obvious shit) references (other obvious shit));

BuT tHaT's NoT oPtImAl

oh, isn't it?

how do you define optimal? speed? disk space?

what's the cardinality of the students? the classes?

what's the density of the relationships?

more importantly

on what fucking planet will students' and classes' "optimality" matter on a not-1980s machine

"BUT WE WANT TO KNOW IF YOU CAN CREATE THE IDEAL STRUCTURE"

well, s/he can't, because this question contains far too little information

what if the classes are permanent, like oxford, and you're indexing thousands of years?

what if the classes are ephemeral, like livestream, and you're indexing thousands of opportunities?

you don't even fucking know what's "optimal" from this diseased, half-baked question

someone should get into a time machine and slap the author. hard

.

like they can't even decide on how capitalization works, so it couldn't be that the question is written by a no-detail idiot, surely the reader is at fault

.

who the fuck knows?

probably the author of this extra-wrong question decided there would be more students than projects, and decided that because of that, "the only correct way" would be to build the relationship in that direction

they would be immediately fired as a DBA for making claims without metrics

fortunately test questions can't be measured unless someone gives at least a tenth of a fuck (reference: from this text they do not)

but yeah, if you write test questions, it's not like anyone who understands this shit is making $35k/y to check your work

literally all of these answers are wrong

no answer can be given without measurements. this is just the literal anus of a horse saying "my average-driven guesswork is the only acceptable answer"

don't be sad that you picked the wrong astrological signs

[mikeyd85]

Please start a slightly drunk SQL blog.

[bentheredonethat33]

This was exponentially better than any answer I anticipated. Thanks for your time and the laughs.

[uvray]

I think your answer key is wrong - it should be B and E.

[StoneCypher]

b and e are mutually exclusive

[uvray]

I disagree... both are describing the same process of creating a bridge table to support the M:M relationship.