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Identify consecutive numbers in a column (at least 3 consecutive).

SQLeasy0.7 min readPremium
Frequency
Low
Asked at 1 company
Category
487
questions in SQL
Difficulty Split
130E|271M|86H
in this category
Total Bank
1,863
across 7 categories
Asked at these companies
Incedo
Expert AnswerPremium
139 wordsInterview-ready
To find at least 3 consecutive numbers: use gaps-and-islands via row numbering. WITH t AS (SELECT num, num - ROW_NUMBER() OVER (ORDER BY num) AS grp FROM numbers), grouped AS (SELECT grp, MIN(num) start_num, MAX(num) end_num, COUNT(*) cnt FROM t GROUP BY grp HAVING COUNT(*) >= 3) SELECT start_num, end_num, cnt FROM grouped. Logic: num - ROW_NUMBER() is constant for consecutive numbers....
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