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Rolling Average Over Last 30 Days

MediumSQL · PostgreSQL00:00
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Your question is Rolling Average Over Last 30 Days. Start with the requirements and the one table on the right.

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Problem

Write a query using SQL window functions to calculate the rolling average of customer engagement over the last 30 days.

Use the engagement_daily table. Include each recorded engagement row, and treat the 30-day period as inclusive of the current date. Rows with a NULL engagement score remain in the output but do not contribute to the average.

Output

  1. Return customer_id, engagement_date, engagement_score, rolling_average, and engagement_id.
  2. Return one row per engagement record, ordered by customer_id, engagement_date, and engagement_id.

Schema

engagement_daily
ColumnTypeDescription
engagement_idPKINTEGERUnique engagement record identifier
customer_idVARCHAR(30)Customer associated with the engagement
engagement_dateDATEDate on which the engagement was recorded
engagement_scoreNUMERIC(10,2)Measured customer engagement score
Tablesengagement_daily
Your solutionPostgreSQL
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