69. Number of happy customers

I'm trying to write a query that returns the number of "happy customers" — defined as customers who made at least one rental on each day of any 2 consecutive days within the date range May 24 to May 31 (inclusive).

📊 Expected Result:
The expected count is 159.

💻 My Environment:

• Database: PostgreSQL

  🧩 What I've Tried So Far:

  • I used LEAD() to compare each customer's rental date with the next one.

  • Filtered where the next date is exactly 1 day ahead.

  • Counted customers with at least one such occurrence.

  ❗ Issue:
  This returns 123, but the expected answer is 159. I'm unsure where the logic fails or whether I'm missing edge cases like multiple rentals in a day or overlapping rental dates.

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  🙏 Would appreciate help with:

  • Identifying if my logic is flawed for how “consecutive rentals” are calculated.

  • Suggestions for improving the query or a different approach entirely.

  Thanks in advance!