Difference Between Row_Number, Rank And Dense_Rank

Question

Vishal Yelve · Answer

Hi Kiran, ROW_NUMBER: It just returns the sequence numbers starts from 1. RANK: Returns the rank of each record in the current result set. DENSE_RANK: It is same as Rank() function. But it returns without gaps in ranking. Rank and Dense_Rank are similar to Row_Number, but when there are ties, they will give the same value to the tied values. rank will keep the ranking, so the numbering may go 1, 2, 2, 4 etc, whereas Dense_Rank will never give any gaps. See below example. CREATE TABLE [Emp] ( [EmpId] INT NOT NULL IDENTITY(1, 1), [Name] VARCHAR(255) NULL, [DeptId] INT NULL, [Salary] INT NULL, PRIMARY KEY ([EmpID]) ); GO TRUNCATE TABLE [Emp] INSERT INTO [Emp] ([Name], DeptId, Salary) VALUES ('Britanni',3,1000), ('Julian',2,2000), ('Dolan',3,3000), ('Jonah',4,4000), ('Fulton',2,5000), ('Scarlett',4,1000), ('Bernard',2,2000), ('Chancellor',1,3000), ('Dalton',4,4500), ('Len',1,5000), ('Bree',4,1000), ('Cooper',1,2000), ('Nora',4,3000), ('Gareth',3,4000), ('Beau',2,5000); SQL Query SELECT *, ROW_NUMBER() OVER(PARTITION BY DeptId ORDER BY Salary) AS RowNumber, RANK() OVER(PARTITION BY DeptId ORDER BY Salary) AS [Rank], DENSE_RANK() OVER(PARTITION BY DeptId ORDER BY Salary) AS [DenseRank] FROM [dbo].[Emp]

Jignesh Kumar · Answer

Hello kiran, You can find my article with detailed example which will help you out to understand, https://www.c-sharpcorner.com/blogs/difference-between-rownumber-rank-denserank-in-sql-server

Muhammad Imran Ansari · Answer

In SQL, ROW_NUMBER() , RANK() , and DENSE_RANK() are window functions used to assign unique values to rows within a partition of a result set. However, they differ in how they handle ties (duplicate values) and the numbering sequence. Here's a breakdown of their differences: ROW_NUMBER(): Assigns a unique sequential integer to each row within a partition, starting from 1. Handling Ties: Does not handle ties. Even if two rows have the same values, they will still receive different row numbers. Use Case: Useful when you need a unique identifier for each row, regardless of duplicate values. SELECT name, score, ROW_NUMBER() OVER (ORDER BY score DESC) AS row_num FROM students; RANK(): Assigns a unique rank to each row within a partition, but leaves gaps in the ranking sequence when there are ties. Handling Ties: Rows with the same values receive the same rank, and the next rank(s) are skipped. Use Case: Useful when you want to rank rows but account for ties, with gaps in the ranking sequence. SELECT name, score, RANK() OVER (ORDER BY score DESC) AS rank FROM students; DENSE_RANK(): Assigns a unique rank to each row within a partition, but does not leave gaps in the ranking sequence when there are ties. Handling Ties: Rows with the same values receive the same rank, and the next rank is not skipped. Use Case: Useful when you want to rank rows without gaps in the ranking sequence, even when there are ties. SELECT name, score, DENSE_RANK() OVER (ORDER BY score DESC) AS dense_rank FROM students;

Rajanikant Hawaldar · Answer

Please refer below article. https://www.c-sharpcorner.com/UploadFile/85ed7a/difference-between-rownumber-rank-and-denserank-in/