S set2018 @setgate added a Question 29 Sep 2017 relational algebra-null value Explain how relational algebra operations deal with NULL values. 5Comments thumbs up down up0 like S set2018 @setgate 2 Oct 2017 08:58 pm shivani1234 explain this concept pls up0 like Log in or register to post comments shivani @shivani1234 3 Oct 2017 12:53 pm Relational algebra consists of several operations like union , intersection , set difference , joins,.. Union : A ∪ NULL = A Intersection : A ∩ NULL =NULL Set difference : A - NULL = A Joins : Natural Join: A X NULL = NULL Left Join : A ⋊ NULL = null Right join : A ⋉ NULL = A up0 like Log in or register to post comments A Akshay Saxena @akshay0612 3 Oct 2017 12:43 pm @shivani1234 right join should be null? up0 like Log in or register to post comments S set2018 @setgate 3 Oct 2017 02:53 pm what about projection ? up0 like Log in or register to post comments shivani @shivani1234 3 Oct 2017 03:17 pm if column attribute has got null values , it will output as null on projection up0 like Log in or register to post comments

shivani1234 explain this concept pls

Relational algebra consists of several operations like union , intersection , set difference , joins,..

Left Join : A ⋊ NULL = null

Right join : A ⋉ NULL = A

@shivani1234 right join should be null?

what about projection ?

if column attribute has got null values , it will output as null on projection