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'31000) ('Julian'22000) ('Dolan'33000) ('Jonah'44000) ('Fulton'25000) ('Scarlett'41000) ('Bernard'22000) ('Chancellor'13000) ('Dalton'44500) ('Len'15000) ('Bree'41000) ('Cooper'12000) ('Nora'43000) ('Gareth'34000) ('Beau'25000); 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]

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;

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

Rajanikant Hawaldar · Answer

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

Difference Between Row_Number, Rank And Dense_Rank