Recent questions tagged goclasses-da-dpp-day-279

Consider the relations:$\mathrm{Users(username, name, email, password, address)}$and$\mathrm{FriendsWith(username, username2, sincewhen)}$.A friendship tuple indicates th...

Consider the relations:$\mathrm{STUDENT(name,regno,gpa,level,dept)}$$\mathrm{COURSE(cno,cname,dept)}$$\mathrm{TAKE(regno,cno)}$Using only the basic relational algebra ope...

Consider $R(a,b)$ and $S(c,d)$.Which relational algebra expression is equivalent to:SELECT a, d FROM R, S WHERE R.a 10 AND R.b = S.c;Use only the basic operators.$\pi_{a...

Let $R$ and $S$ be union-compatible relations.Which expression computes $R\cap S$ using only union and set difference?$(R\cup S)-((R-S)\cup(S-R))$ $(R\cup S)-(R-S)$ $(R-S...

Consider $\text{parts(pno, pname, price)}$.Which relational algebra expression returns exactly the names of all parts whose price is greater than $\$200$?$\pi_{\text{pnam...