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Window Functions: ROW_NUMBER(), RANK(), PARTITION BY - produce output using dataset

SQLmedium0.4 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
Wolters Kluwer
Key Concepts Tested
partitionwindow
Expert AnswerPremium
84 wordsInterview-ready
Example: employees (id, name, dept, salary). **ROW_NUMBER**: SELECT *, ROW_NUMBER() OVER (PARTITION BY dept ORDER BY salary DESC) rn FROM employees. **RANK**: Same but RANK()—ties get same rank, gap after. **DENSE_RANK**: Same rank, no gap. Output: dept, name, salary, rn, rank, dense_rank. **Why PARTITION BY**: Defines groups; ORDER BY defines order within group. Use ROW_NUMBER for unique ordering; RANK for Olympics-style; DENSE_RANK for top-N without gaps....
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