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Problem solution · SQL

Team Dominance by Pass Success

Team Dominance by Pass Success: a SQL solution using relational aggregation. Learn the idea, check the complexity, and read the full code, with credit to walkccc LeetCode Solutions.

Technique
Relational aggregation
Source
walkccc LeetCode Solutions
Length
26 lines
Start with the idea.

Try the problem first. If you get stuck, read the approach below, then write your own solution. The full code is at the bottom.

Approach

Relational aggregation

For Team Dominance by Pass Success, the query transforms and combines relational rows, then filters or aggregates them into the requested result.

  1. Identify the source rows and join keys.
  2. Apply filters before aggregation when possible.
  3. Group, rank, or project the final columns required by the result.

Code notes

  • 26 lines of SQL from the credited upstream file 3384.sql.
  • The implementation keeps its working state in language-native values and containers.
  • No explicit loop blocks detected.

Complexity

Review join cardinality, grouping keys, and available indexes when estimating query cost.

Check the problem constraints before deciding whether this complexity will pass.

Source

Code and credit

This code comes from walkccc LeetCode Solutions by P.-Y. Chen (walkccc) and is used under the MIT licence.

Open problem ↗Original source ↗
Full codeTeam Dominance by Pass Success · SQLSQL
Use this to learn the idea, then write your own version.
WITH  PassDetails AS (    SELECT      Passes.pass_from,      Passes.pass_to,      Passes.time_stamp,      Team1.team_name AS from_team,      Team2.team_name AS to_team,      CASE        WHEN Passes.time_stamp BETWEEN '00:00' AND '45:00' THEN 1        WHEN Passes.time_stamp BETWEEN '45:01' AND '90:00' THEN 2      END AS half_number    FROM Passes    INNER JOIN Teams AS Team1      ON (Passes.pass_from = Team1.player_id)    INNER JOIN Teams AS Team2      ON (Passes.pass_to = Team2.player_id)  )SELECT  from_team AS team_name,  half_number,  SUM(IF(from_team = to_team, 1, -1)) AS dominanceFROM PassDetailsGROUP BY 1, 2ORDER BY 1, 2;

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