+1 vote
184 views
in Database Management Systems by

1 Answer

+1 vote
by
selected by (user.guest)
 
Best answer

Entity Integrity Constraints

The primary key attribute, PK, of any relational schema R in a database cannot have null values in any tuple. In other words, for each table in a DB, there must be a key; for each key, every row in the table must have non-null values. This is because PK is used to identify the individual tuples.  

Mathematically, t[PK] != NULL for any tuple t € r( R).

Related questions

+1 vote
1 answer 613 views
+1 vote
1 answer 195 views
+2 votes
1 answer 7.1k views
+1 vote
1 answer 78 views
+1 vote
1 answer 88 views
+1 vote
1 answer 80 views
+1 vote
1 answer 48 views
0 votes
1 answer 26 views
0 votes
1 answer 75 views
0 votes
1 answer 75 views
+1 vote
1 answer 95 views
+1 vote
1 answer 120 views
+1 vote
1 answer 163 views
+1 vote
1 answer 201 views
+1 vote
1 answer 94 views
+2 votes
1 answer 420 views
+2 votes
1 answer 510 views
+2 votes
1 answer 764 views
+2 votes
1 answer 384 views
+1 vote
1 answer 501 views
+2 votes
1 answer 486 views
+1 vote
1 answer 592 views
+1 vote
1 answer 331 views
+1 vote
0 answers 16 views
+1 vote
1 answer 34 views
+1 vote
1 answer 36 views
+1 vote
1 answer 36 views
0 votes
1 answer 83 views
+1 vote
1 answer 42 views
0 votes
1 answer 64 views
asked Oct 25 in Database Management Systems by (user.guest)
0 votes
1 answer 83 views
asked Sep 23 in Database Management Systems by (user.guest)
+1 vote
1 answer 71 views
+1 vote
1 answer 74 views
asked Sep 23 in Database Management Systems by anonymous
+1 vote
1 answer 154 views
Welcome to CPENTalk.com
Solution-oriented students of computer engineering on one platform to get you that

ONE SOLUTION

...