PostgreSQL Exam PGCES-02 Topic 9 Question 25 Discussion

Actual exam question for PostgreSQL's PGCES-02 exam

Question #: 25
Topic #: 9

A table is defined as below. Select the most suitable description about the foreign key constraint. CREATE TABLE master (id INTEGER PRIMARY KEY, name TEXT); CREATE TABLE record (id INTEGER REFERENCES master (id), count INTEGER);

AIf any row exists in the 'record' table, no change can be made to the 'master' table.

BIf the 'record' table contains a row with an 'id', no change can be made at all to the corresponding 'id' row in the 'master' table.

CIf the 'record' table contains a row with an 'id', the corresponding 'id' row in the 'master' table cannot be deleted.

DThe 'record' table cannot have duplicate 'id's.

EThese SQL statements are invalid; no constraints are created.

Show Suggested Answer

Suggested Answer: A

by Veronika at May 07, 2022, 02:41 AM

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Valda

2 months ago

I'm just impressed they managed to fit all this into a single exam question. That's some serious database compression right there!

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Royal

8 days ago

D) The 'record' table cannot have duplicate 'id's.

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Domonique

19 days ago

C) If the 'record' table contains a row with an 'id', the corresponding 'id' row in the 'master' table cannot be deleted.

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Ty

21 days ago

B) If the 'record' table contains a row with an 'id', no change can be made at all to the corresponding 'id' row in the 'master' table.

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Carri

21 days ago

C) If the 'record' table contains a row with an 'id', the corresponding 'id' row in the 'master' table cannot be deleted.

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Leah

22 days ago

B) If the 'record' table contains a row with an 'id', no change can be made at all to the corresponding 'id' row in the 'master' table.

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Julie

1 months ago

A) If any row exists in the 'record' table, no change can be made to the 'master' table.

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Karma

1 months ago

A) If any row exists in the 'record' table, no change can be made to the 'master' table.

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Cammy

1 months ago

Exactly, it's a way to link the two tables together and prevent any inconsistencies.

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Tanesha

2 months ago

So, basically, the foreign key constraint ensures that you can't delete a record in the 'master' table if it's being referenced in the 'record' table.

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Latonia

2 months ago

I agree, that sounds right. It's all about maintaining data integrity.

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Fanny

2 months ago

I think the answer is C) If the 'record' table contains a row with an 'id', the corresponding 'id' row in the 'master' table cannot be deleted.

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Verdell

2 months ago

Option E? Really? These are perfectly valid SQL statements. Someone needs to brush up on their database knowledge.

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Avery

2 months ago

Haha, good thing the 'record' table doesn't have a column called 'count_of_beers'. That would be a whole different kind of foreign key constraint!

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Dominic

2 months ago

C) If the 'record' table contains a row with an 'id', the corresponding 'id' row in the 'master' table cannot be deleted.

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Nickole

2 months ago

A) If any row exists in the 'record' table, no change can be made to the 'master' table.

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Dion

2 months ago

I agree with Stephane. This is a classic example of a foreign key constraint, which prevents orphaned records in the dependent table.

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Stephane

2 months ago

Option C is the correct answer. The foreign key constraint ensures that the corresponding row in the master table cannot be deleted if there is a reference to it in the record table.

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