ahojte. chcela by som sa spytat ci niekto, kto sa vyzna v exceli, by mi vedel pomoct najst odpoved na jeden priklad, tykajuci sa operacii s relacnymi algebrami, cize s tabulkami. konkretne ide o tento:
Consider the following schema of tables:
Employee(person_name, street, city)
Works(person_name, company_name, salary)
Company(company_name, city)
Manages(person_name, manager_name)
a dalej zadanie je taketo:
Please use the tables as the basis for these questions:
Give an expression or a formula in relational algebra to express each of the following queries:
1. Find the names of all employees who earn more than their managers
2. Find the names of all employees who live in the same city and on the same street as their managers
3. Find the names of all employees within the database that do not work for "BNY Mellon"
4. Find the names of all employees in the database who earn more than the top earner at "BNY Mellon" in the database.
Vsetky udaje v tabulkach, ako napr ako person_name, street atd si samozrejme mozem vymysliet, no uz vyse tyzdna si lamem hlavu s tym, ake funkcie mam poucit aby som dosla k jednotlivym rieseniam. Preto ak by ste mi aspon s tymto niekto vedeli pomoct, bola by som vam velmi vdacna. Ak by to niekto potreboval prelozit, staci napisat.
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