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 5.3k views answer comment Share Follow See all 0 reply Please log in or register to add a comment.
Best answer 46 votes 46 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.