# Basics of Sets and Relations #6

# Basics of Sets and Relations #6

thomas_ejob + 1 comment The answer is 2 but I don't understand why.

- PD
Priyadharshini_R + 1 comment because they have asked about attribute values...only two attributes are specified in the column

priyankasomyaco1 + 1 comment what are those 2 values

ayushchauhan_ + 0 comments It will return only NAME and NUMBER from the table not SEX. So the answer is 2.

frostshoxx + 0 comments I think you guys are over thinking about it

What is the count of attributes (columns) returned in the following projection? π(Name, Number)(Student)

There are name and number, so there you have 2 columns/attributes.

Amarillia + 0 comments http://jcsites.juniata.edu/faculty/rhodes/dbms/relalg.htm

I found this. Maybe it will help.

- IC
italocid + 1 comment Hi everybody, How should I have to take this ->

"π(Name, Number)(Student)"? what is the meaning of that, because I don´t get it.Thnx

- AA
Adya0711 + 4 comments http://web.cse.ohio-state.edu/~gurari/course/cse670/html/cse670Ch4.html

Explanation given in 4.6 section of above link

- IC
italocid + 0 comments thnx Adya0711 for that usefull link =)

ganeshshsf + 0 comments Thanks Adya0711

amiro + 0 comments Hi Adya0711, could you please check the link. I got the "Page not Found" error.

thanks in advance

vibhor3 + 0 comments link has been removed, please repost a new link

- RH
kr_insang + 0 comments Is there a compiled list of which db operations corresponds to which notation?

- A
anjitha3021 + 0 comments So shouldn't the answer be 6.... 3 names n 3 numbers??

- AI
ashiqi + 0 comments Projection means number of columns in a query.

select x, y, z from YourTable

x, y, z is the projection here.

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