+1 vote
177 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 601 views
+1 vote
1 answer 185 views
+2 votes
1 answer 7.0k views
+1 vote
1 answer 71 views
+1 vote
1 answer 81 views
+1 vote
1 answer 75 views
+1 vote
1 answer 39 views
0 votes
1 answer 62 views
0 votes
1 answer 61 views
+1 vote
1 answer 81 views
+1 vote
1 answer 113 views
+1 vote
1 answer 152 views
+1 vote
1 answer 190 views
+1 vote
1 answer 88 views
+2 votes
1 answer 408 views
+2 votes
1 answer 502 views
+2 votes
1 answer 754 views
+2 votes
1 answer 378 views
+1 vote
1 answer 490 views
+2 votes
1 answer 478 views
+1 vote
1 answer 579 views
+1 vote
1 answer 325 views
+1 vote
0 answers 11 views
+1 vote
1 answer 25 views
+1 vote
1 answer 28 views
+1 vote
1 answer 29 views
0 votes
1 answer 71 views
+1 vote
1 answer 36 views
0 votes
1 answer 57 views
asked Oct 25 in Database Management Systems by (user.guest)
0 votes
1 answer 77 views
asked Sep 23 in Database Management Systems by (user.guest)
+1 vote
1 answer 64 views
+1 vote
1 answer 68 views
asked Sep 23 in Database Management Systems by anonymous
+1 vote
1 answer 138 views
+1 vote
1 answer 183 views
Welcome to CPENTalk.com
Solution-oriented students of computer engineering on one platform to get you that

ONE SOLUTION

...