Consider the following two tables named Raider and Team in a relational…
2024
Consider the following two tables named Raider and Team in a relational database maintained by a Kabaddi league. The attribute ID in table Team references the primary key of the Raider table, ID.
The SQL query described below is executed on this database:
SELECT * FROM Raider, Team WHERE Raider.ID=Team.ID AND City=“Jaipur” AND RaidPoints > 200;
The number of rows returned by this query is ______.
Attempted by 159 students.
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Correct answer: 3
Solution: determine which rows satisfy the join and the filters.
Step 1: Find Team rows with City = Jaipur. These rows have IDs 2, 1, and 6 (Team entries: ID 2, ID 1, ID 6).
Step 2: Find Raider rows with RaidPoints > 200. These are ID 1 (Arjun, RaidPoints 250), ID 2 (Ankush, RaidPoints 219), ID 5 (Pratham, RaidPoints 220), and ID 6 (Gopal, RaidPoints 215).
Step 3: Apply the join Raider.ID = Team.ID. The IDs present in both the Jaipur teams and the high-scoring raiders are 1, 2, and 6. These produce three joined rows:
ID 1: Raider Arjun (RaidPoints 250) joined with Team row for Jaipur (BidPoints 250).
ID 2: Raider Ankush (RaidPoints 219) joined with Team row for Jaipur (BidPoints 200).
ID 6: Raider Gopal (RaidPoints 215) joined with Team row for Jaipur (BidPoints 200).
Answer: 3 rows