Querying Data for a User Need

A query is meaningful when it answers a user question. Begin with the need, then choose fields, filters, calculations and order.

Example need

A participant wants to find the strongest fictional teams and inspect their performance.

SELECT team_name,
       SUM(wins) AS total_wins,
       SUM(losses) AS total_losses
FROM team_results
GROUP BY team_name
ORDER BY total_wins DESC, team_name ASC;

This processes many stored rows into one summary per team. It is stronger evidence of processing than simply displaying the imported table.

Plan the output

Document:

• user and question
• required source fields
• processing or calculation
• useful order/filter
• output form
• success criterion supported

Check

• The query answers a stated need.
• Only required fields are used.
• Grouping and calculations are correct.
• Empty results are handled.
• Output can be tested against known fictional data.