35 votes 35 votes A library relational database system uses the following schema USERS (User#, User Name, Home Town) BOOKS (Book#, Book Title, Author Name) ISSUED (Book#, User#, Date) Explain in one English sentence, what each of the following relational algebra queries is designed to determine $\sigma_{ \text{User#}=6}\left(\pi_{\text{User#, Book Title}}\left(\left(\text{USERS} \bowtie \text{ISSUED}\right) \bowtie \text{BOOKS}\right)\right)$ $\pi_{\text{Author Name}}\left(\text{BOOKS} \bowtie \sigma_{\text{Home Town=Delhi}} \left(\text{USERS} \bowtie \text{ISSUED}\right)\right)$ Databases gate1996 databases relational-algebra descriptive + – Kathleen asked Oct 9, 2014 • edited Oct 14, 2014 by Arjun Kathleen 5.4k views answer comment Share Follow See all 0 reply Please log in or register to add a comment.
Best answer 47 votes 47 votes Select the (user# and) titles of the books issued to User# 6 Select author names of the books issued to users whose home town is Delhi Arjun answered Oct 14, 2014 • edited Oct 15, 2018 by kenzou Arjun comment Share Follow See all 0 reply Please log in or register to add a comment.
10 votes 10 votes (a) select all the book title which are issued by user id =6 (b) select all the author name whose book are issued by user belongs to home town delhi saket nandan answered Jul 1, 2015 saket nandan comment Share Follow See all 0 reply Please log in or register to add a comment.