0 votes 0 votes 1.A primary key cannot be NULL (Any of its attributes can’t be NULL) 2.can candidate key be NULL(All attr) (Other than primary keys i,e alternate keys) 3.can some attributes of candidate key be NULL?? which of these are true . false Databases databases + – jatin khachane 1 asked Jan 14, 2019 jatin khachane 1 927 views answer comment Share Follow See all 7 Comments See all 7 7 Comments reply Show 4 previous comments Shubhgupta commented Jan 14, 2019 reply Follow Share in that case candidate key termed as primary key where prime can not be null otherwise it termed as alternate key. A prime attribute is a part of candidate key where key is primary key. 0 votes 0 votes jatin khachane 1 commented Jan 14, 2019 reply Follow Share can you explain little more about candidate key and alternate keys which can be null and which not ...it so confusing for me :( 0 votes 0 votes anjali007 commented Jan 14, 2019 reply Follow Share see primary key cant be null ..candidate keys other than the primary key may be null i.e alternate keys may be null 0 votes 0 votes Please log in or register to add a comment.
0 votes 0 votes Primary key cannot be Null but Candidate key apart from Primary key may have Null values Sanandan answered Aug 23, 2020 Sanandan comment Share Follow See all 0 reply Please log in or register to add a comment.