Show all pairs of authors who have responded to each other's posts (Person A has responded...

Transcribed Image Text:

Show all pairs of authors who have responded to each other's posts (Person A has responded to any of Person B's posts, and Person B has responded to any of Person A's posts). Format usernames as 20 characters wide and sort in alphabetical order by first author followed by second author. Use subqueries in the FROM/JOIN clauses. Hint: First, write a query that finds all pairs of authors where Author A has responded to Author B's post. Then, write an outer query that joins two copies of the first query together, and matches Author A in the first subquery to Author B in the second subquery, and matches Author B in the first subquery to Author A in the second subquery. Correct answers will look like this: First Author Alan. Turing Alan Turing fox.henry jordon.fuchs jordon.fuchs scott.ashley Second Author jordon.fuchs scott.ashley jordon.fuchs Alan. Turing fox.henry Alan Turing Show all pairs of authors who have responded to each other's posts (Person A has responded to any of Person B's posts, and Person B has responded to any of Person A's posts). Format usernames as 20 characters wide and sort in alphabetical order by first author followed by second author. Use subqueries in the FROM/JOIN clauses. Hint: First, write a query that finds all pairs of authors where Author A has responded to Author B's post. Then, write an outer query that joins two copies of the first query together, and matches Author A in the first subquery to Author B in the second subquery, and matches Author B in the first subquery to Author A in the second subquery. Correct answers will look like this: First Author Alan. Turing Alan Turing fox.henry jordon.fuchs jordon.fuchs scott.ashley Second Author jordon.fuchs scott.ashley jordon.fuchs Alan. Turing fox.henry Alan Turing

Answer rating: 100% (QA)

Answer SQL code SELECT SUBQ1author AS First Author SUBQ2author AS Second Author FROM S... View the full answer