![Computers and Technology](/tpl/images/cats/informatica.png)
Computers and Technology, 25.11.2021 14:00, townykid96
Consider a social network database about people and their relationships. The database has two relations: Person ( pid, name ) Relationship ( pid1, rel, pid2 ) The key fields are underlined: Person. pid is the key for Person, and Relationship. pid1 and Relationship. pid2 are foreign keys to Person. rel is a string representing the relationship type, and it can only be ’friend’ or ’enemy’. So, a tuple (1,’friend’,2), means that the person with id 1 considers the person with id 2 a friend. Note that the relationship is not symmetric: if Alice is friend with Bob, it does not imply that Bob is friend with Alice. Create a view called mutual that contains pairs of people who share mutual feelings for each other (i. e., they consider each other friends or enemies). The schema of your view should be mutual(name1,name2). Note that your view should not repeat the same pair of people in different order (e. g., (Alice, Bob) and (Bob, Alice)); your view should only keep the pair, such that the name with the lowest pid appears first.
![answer](/tpl/images/cats/otvet.png)
Answers: 1
Other questions on the subject: Computers and Technology
![image](/tpl/images/cats/informatica.png)
![image](/tpl/images/cats/informatica.png)
![image](/tpl/images/cats/informatica.png)
Computers and Technology, 24.06.2019 00:40, dheydar3506
What is the error in the following pseudocode? module main() call raisetopower(2, 1.5) end module module raisetopower(real value, integer power) declare real result set result = value^power display result end module
Answers: 1
![image](/tpl/images/cats/informatica.png)
Computers and Technology, 24.06.2019 13:30, lorelaistudent
Does anybody know how to hack into a google account? i had important information on it and it is gone now and i need getting it back.
Answers: 1
Do you know the correct answer?
Consider a social network database about people and their relationships. The database has two relati...
Questions in other subjects:
![Konu](/tpl/images/cats/health.png)
![Konu](/tpl/images/cats/himiya.png)
Chemistry, 23.04.2020 00:24
![Konu](/tpl/images/cats/en.png)
![Konu](/tpl/images/cats/mat.png)
Mathematics, 23.04.2020 00:24
![Konu](/tpl/images/cats/obshestvoznanie.png)
![Konu](/tpl/images/cats/mat.png)
![Konu](/tpl/images/cats/informatica.png)
![Konu](/tpl/images/cats/mat.png)
Mathematics, 23.04.2020 00:24
![Konu](/tpl/images/cats/biologiya.png)
![Konu](/tpl/images/cats/en.png)
English, 23.04.2020 00:24