Discuss PostgreSQL PGCES-02 Exam Topic 3 Question 4

SQL statements were executed in the following order:

CREATE TABLE fmaster

(id INTEGER PRIMARY KEY, name TEXT);

CREATE TABLE ftrans

(id INTEGER REFERENCES fmaster (id), stat INTEGER, date DATE);

INSERT INTO fmaster VALUES (1, 'itemA');

INSERT INTO ftrans VALUES (1, 1, CURRENT_DATE);

Select two SQL statements that will generate an error when executed next.

AINSERT INTO ftrans VALUES (1, 1, CURRENT_DATE);

BINSERT INTO ftrans VALUES (2, 1, '2007-07-07');

CUPDATE fmaster SET name = 'itemAX' WHERE id = 1;

DUPDATE fmaster SET id = 100 WHERE id = 1;

EUPDATE ftrans SET id = 200 WHERE id = 1;

Suggested Answer: A, C

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12 comments · newest first

Mindy 11 months ago

Wait, can you really update the id in ftrans? That seems risky.

Dulce 11 months ago

D is a big no-no! Can't change primary key values like that.

Maile 12 months ago

No way, C is fine! It updates a name, not an id.

Felicia 12 months ago

I think B might also throw an error since id 2 doesn't exist.

Naomi 12 months ago

A and D will definitely cause errors.

Lavonna 1 year ago

I’m a bit confused about option A. Didn’t we already insert that same value? Would it cause a duplicate key error?

Queen 1 year ago

I remember a practice question where we had to check foreign key constraints. I think option E will throw an error because 200 isn't a valid reference in fmaster.

Lemuel 1 year ago

I'm not entirely sure, but I feel like option D could also cause an issue since changing the primary key might break something.

Glory 1 year ago

I think option B might generate an error because the ID 2 doesn't exist in fmaster, right?

Eliseo 1 year ago

This question seems straightforward, I think I know the answer based on my understanding of SIP URI dialing.

Meaghan 1 year ago

I'm a bit confused on this question. I know InnoDB encryption is supposed to be transparent, but I'm not sure if that means it supports all indexes transparently. I'll have to think about that one.

Kenda 1 year ago

The discount rate seems like it could be an issue, but I'm not entirely sure. I'll need to review the rationale for using 10% and see if that's the right approach.

PostgreSQL PGCES-02 Exam - Topic 3 Question 4 Discussion