Consider a database name “interviewmania” whose attributes

Home » MYSQL » Mysql miscellaneous » Question

Consider a database name “interviewmania” whose attributes are internid (primary key), subject, subjectvalue.
Internid = {1, 2, 3, 4, 5, 6}
Subject = {sql, oop, sql, oop, c, c++}
Subjectvalue = {0, 0, 1, 1, 2, 2, 3, 3}
If these are one to one relation then what will be the output of the following query?
```
SELECT internid
FROM interviewmania
WHERE subject IN (SELECT subject FROM interviewmania WHERE subjectvalue IN (3, 2));
```

1. {1, 2, 3, 4, 5, 6}
2. {3, 4}
3. {1, 2, 3}
4. {5, 6}
5. None of these

Correct Option: A

Only those value will be selected whose subjects are c, c++, sql, oop. In the sub query subject_value=3 OR 2 which belongs to subject {c, c++, sql, oop} after that this subject belong to intern_id (1, 2, 3, 4, 5, 6).