question

zashwin avatar image
zashwin asked

Please help with the following queries. Rectify if they are wrong.

[Refer this link for the questions>>][1] My answers till now,(by the way I solved them but I am not sure if they are correct, so I wanted to get something like a model answer paper to compare and check.) Answer.2) select name from Artist A where exists(select name from album B where A.name=B.name) Answer.3)select A.name from Atist A, Track T, TrackList L where A.artistID=L.trackID and L.Tracknum=1 and T.name="Intro" Answer.4)select artist.name from Artist where artist.name="Mogwai" and weight>(select weight from Artist,SimilarArtist where Artist.artistID=SimilarArtist.artistID) Answer.5)select A.name from Album A,Tracklist L where L.tracknum>30 and L.albumID=A.albumID M not getting the other answers. So if nething wrong in the above pls rectify. [1]: http://inst.eecs.berkeley.edu/~cs186/fa06/hw/hw3/hw3.pdf
queryjoinsquery-planquery-designer
1 comment
10 |1200

Up to 2 attachments (including images) can be used with a maximum of 512.0 KiB each and 1.0 MiB total.

We closed the original question as there was no real substance to it. As posters have said, if the OP wants to post the questions as questions, rather than just a link, we will be happy to help.
1 Like 1 ·

1 Answer

Grant Fritchey avatar image
Grant Fritchey answered
Answer 3 is a cartesian join, so you'll want to look at that. Other than that, are you sure you took the class? I'd strongly suggest you study the provided book a bit more.
4 comments
10 |1200

Up to 2 attachments (including images) can be used with a maximum of 512.0 KiB each and 1.0 MiB total.

Maybe he should read your books instead! :)
0 Likes 0 ·
I wasn't sure, seeing as the course said 'due in 2006'. So I figure either: * a - OP is a time traveller from the future, and probably doesn't need basic SQL help * b - OP is **very** late with homework, so probably won't matter if it's wrong anyway
0 Likes 0 ·
I reckon OP is in the wrong place, anyway. Judging by Homework 2, it's a Postgres environment...
0 Likes 0 ·
Postgres or not, there's no join criteria for Track in that query. He's going to get some nasty data back.
0 Likes 0 ·