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Find all subreddits that had zero non-deleted posts in March 2026. A subreddit should be excluded if any non-deleted posts exist for dates between March 1 and March 31, 2026. Return columns: subreddit_id, subreddit_name. Order by subreddit_name ascending.
Calculate the 7-day rolling average of daily active commenters. For each day, first count the number of distinct non-deleted commenters. Then compute a rolling window that averages the daily active commenters over the current day plus the previous 6 days (7-day window). Return columns: comment_date, daily_active (count of distinct non-deleted authors per day), rolling_7d_avg (the 7-day rolling average). Order by comment_date ascending.
Find the top 3 most engaging posts (by engagement rate) in each subreddit from Feb 27 to Mar 29, 2026. Engagement is calculated as the sum of absolute score and non-deleted comment count. Engagement rate is engagement divided by total views. Only include posts with at least 50 views, and only include subreddits where the total view count across all qualifying posts is at least 100. Return columns: subreddit_name, post_id, engagement_rate (rounded to 2 decimals), rnk (dense rank within subreddit). Order by subreddit_name and rnk ascending.
3 Reddit problems, each with its own dataset. Click one and you’re in the workspace, free, right in your browser.
Your dataset
subreddit_id (INTEGER) · subreddit_name (VARCHAR) · created_date (DATE) · subscriber_count (INTEGER)
post_id (INTEGER) · subreddit_id (INTEGER) · author_id (INTEGER) · post_date (DATE) · title (VARCHAR) · score (INTEGER) · is_deleted (BOOLEAN)
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Practice Reddit SQL free188 SQL practice questions. 23 companies. Free access to every problem.