Q: In this SQL query, does the second `strftime()` help find the first episode released each year?

[Rajeev Bagra]

Context Code

SELECT
    strftime('%Y', air_date) AS year,
    strftime('%m-%d', MIN(air_date)) AS first_release
FROM episodes
GROUP BY year;

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Answer

No — the second strftime() does not help find the first episode of each year.

The earliest episode per year is found by MIN(air_date), not by strftime().

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Explanation in Simple Terms

This query has three different jobs, and each part does only one job.

1. Extracting the year

strftime('%Y', air_date)

• Runs on every row
• Extracts the year from air_date
• Does not remove or filter rows

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2. Grouping episodes by year

GROUP BY year

• Combines all episodes from the same year into one group
• Creates one output row per year
• Still does not decide which episode is chosen

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3. Finding the first episode of the year

MIN(air_date)

• Looks inside each year group
• Selects the earliest air date
• This is the step that actually finds the first episode

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4. Formatting the result

strftime('%m-%d', MIN(air_date))

• Converts the earliest date into month-day format
• Only affects display
• Has no role in selecting rows

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Why the confusion happens

Because the query outputs the first day of the year, it can feel like:

“The second strftime() found the first episode.”

But in reality:

• The episode is already chosen by MIN(air_date)
• strftime() just makes the date look nicer

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Important Rule to Remember

SQL Component	Selects the first row?
strftime()	❌ No
GROUP BY	❌ No
MIN()	✅ Yes

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One-Sentence Takeaway

MIN(air_date) determines the first episode released each year, while strftime() only formats the date and never influences which row is selected.

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