edited by
682 views
1 votes
1 votes

Consider the following instance R.

A 1 2 3 4
B Null 1 2 2

The number of tuples returned by the following SQL query is _____________.
> select * from R as R1
   where not exists (select * from R)  where B = R1.A                          

edited by

1 Answer

Related questions

1 votes
1 votes
2 answers
1
Purple asked Jan 9, 2017
483 views
Consider the following instances $R.$A1234BNull122The number of tuples returned by the following $\text{SQL query}$ is$?$$>$select $*$ from $R$ as $R_{1}$ where not exist...
0 votes
0 votes
1 answer
2