If I were to have an online shopping website that sold apples and monitors and these were stored in different tables because the distinguishing property of apples is colour and that of monitors is resolution how would I add these both to an invoice table whilst still retaining referential integrity and not unioning these tables? ...
It's commonly understood that in the relational model: Every relational operation should yield a relation. Relations, being sets, cannot contain duplicate rows. Imagine a 'USERS' relation that contains the following data. ID FIRST_NAME LAST_NAME 1 Mark Stone 2 Jane Stone 3 Michael Stone If someone runs a query se...
This is not a homework, but new task assign by superior. To create a system for in-house end-users, which auto suggest to different assembly line based on each line's capacity. Users need to maintain each line capacity everymonth, and each line have its own product group running on it with unique prority on each assembly line. When the...
Hi, I'm starting a project where I want to try to recognize relational algebra's in java-like programming language. For example, given two relations: AmericanActor(Name) EuropianActor(Name) The following expression in RA: AmericanActor U EuropianActor should be equivalent to the following program: void RAMethod(Set<Name> AmericanA...
I'm looking for either a web-based or Windows-based way to point to a relational data source using automated schema exploration (or, even better, a reflection-based approach that would work on any IQueryable in-memory data source) and allow easy exploration of data, traversing between records in related tables, etc. Basically a dynamic ...
We have three entities called Product, ProductType, and ProductCategory. Let's pretend we have three kinds of ProductType: Book, Music, and Video. We have three different ProductCategory's for Book: Fiction, Novel, Technical. Three different ProductCategory's for Music: Rock, Jazz, Pop. And we have three different ProductCategory'...