It's important to follow the instructions closely and use a subquery where indicated, as failure to do so may lead to losing marks.

ANONYMOUS wrote If you know how to perform a left outer join, understanding a right outer join becomes easy because the logic is essentially the same but reversed.

BCNF requires that for any non-trivial functional dependency in a relation, X must be a superkey. This means that the left-hand side of the functional dependency must be a superkey for the relation. The answer should be d. Because in all o...

For Q5, I recommend closely following both the ERD model and the case study.

For the SQL section, you receive marks instantly because you can check your answers in your first attempt. And MCQs allow only one attempt.

I think these two pictures you provided describe the same concept regarding a 1 1 relationship with mandatory participation on one side. Client is designated as the parent (since every client exists, even if they don't have a preference).Preference is...

You can have a look at Week 7 slide, these are very helpful.

Yes, you can do project 2 with someone else.

You can use "SELECT FROM" table name to take a look.

You are correct in using EXCEPT with IN, as it achieves the same goal. The hint suggests using UNION likely for clarity or to explicitly combine job types 'R' and 'H' before filtering. It is simply an exercise in using UNION, but both approaches shou...

It is typically sufficient to connect the entities (tables) themselves.

I think being a nominated driver does not constitute "doing business" with the company, nominated drivers are recorded as part of a vehicle hire transaction, only their information is recorded.

Dr. Nasim has provided some good samples of how to write these dictionaries in the slides on LMS.

You should not write down the Foreign Keys in your dictionaries; all four of your dictionaries should match your conceptual ERD diagram.

GROUP BY in SQL is to group rows that share a common value in one or more columns so that you can apply aggregate functions (like AVG(),COUNT(), etc.) on each group separately. Without GROUP BY, aggregate functions will operate on the entire result s...

I think youou can solve the problem both ways,using a subquery with NOT IN,or using a LEFT JOIN to achieve the same result. But the hint encourages the use of a subquery to practice that method. You can have a try with both approaches in your terminal...

"Where" filters rows before any grouping or aggregation is done,you cannot use aggregate functions (like AVG, COUNT, etc.) directly in the "WHERE" clause because the aggregation happens after the filtering is done. "Having" is used specifically to fi...

yeah, I know what you mean. Our expected output based on the given data should be both IRN and IWS. But when we're intersecting the results of two queries,there are no common item ids between these two, this part of the query is returning nothing,as ...

I think it s great that you are considering the billing and invoicing aspect. It makes sense to include an invoice or billing table to link all the relevant data together (e.g., client, vehicle, tariffs, number of days hired, insurance details),whi...

1.Yes, there can be relationships between multiple entities.For example, as per the case study, a vehicle can be related to a depot (where it is stored or picked up) and a client (who hires it).You are free to infer and add additional relationships a...

Based on the limited data provided, we would get the output "IWS." For this question, we need to select the item ids that are either IRN (associated with 'INK-RESIN') or IWS (associated with 'INK-WRSOL'), and then remove(we should use another operati...

If you're unsure how to write the data types in the dictionary, you can refer to a lab previous database file (such as DreamHomeRental.db or printing.db) and use the ".schema" to review them. The notation (N x) should indicate an integer with a lengt...

I think the correct answer shoulb be 6. First we compute the projection a,b from R, we can get (1,2) and (2,2)(we will delete the duplicate row), then the projection a,c from T (3,2)(2,2)and(1,2), lastly we perform the Cartesian product,which involves ...

Project will be graded based on the performance in the take home test.

You are encouraged to identify fan trap and chasm trap in the first project. But don't worry, you will be provided a solution ERD after project1. You can proceed with Project 2 using this ERD.

As you said An entity type is a broader classification that groups similar entities together, it contains structure and properties. An entity, we can see it as a single instance of entity type. In ER diagrams we can use the rectangle labeled (e.g "St...

yes, C is the correct answer.

All column names in SELECT list must appear in GROUP BY clause unless name is used only in an aggregate function. For this solution, we "SELECT job id, po date", but only "GROUP BY job id".