Are there any functions in MySQL like dense_rank() and row_number() like Oracle?

Question

Are there any functions in MySQL like dense_rank() and row_number() like those provided by Oracle and other DBMS?

I want to generate an id within the query, but in MySQL these functions are not there. Is there an alternative?

Morsel

Simple answer is NO you have to use user defined variables and calculate manually in query – Uphemia

How to calculate manually in query can you tell me i am new to mysql @MKhalidJunaid – Morsel

https://mcmap.net/q/1326703/-mysql-equivalent-of-oracles-rank – Dercy

Rownum in mysql: dev.mysql.com/doc/internals/en/procedure-rownum.html – Philipines

Answer 1

Mysql doesn't have them, but you can simulate row_number() with the following expression that uses a user defined variable:

(@row := ifnull(@row, 0) + 1)

like this:

select *, (@row := ifnull(@row, 0) + 1) row_number
from mytable
order by id

but if you're reusing the session, @row will still be set, so you'll need to reset it like this instead:

set @row := 0;
select *, (@row := @row + 1) row_number
from mytable
order by 1;

See SQLFiddle.

dense_rank() is possible but a train wreck; I advise handling that requirement in the app layer.

Amoy

But the numbers are keep on increasing how many times i execute the query. – Morsel

@Morsel see edit for how to overcome the "ever-increasing row number" problem. – Amoy

Answer 2

We have now..

select ename, sal, dense_rank() over (order by sal desc)rnk
from emp2 e
order by rnk;

Cila

Answer 3

In MySql you dont have dense_rank() or row_number() like the one in Oracle.

But you can create the same functionality through SQL query:

Here is an article doing the same:

dense_rank()

row_number()

Shaving

Answer 4

MySQL doesn't support these functions, but you can mimic them yourself. Shamelessly link to my solution to ROW_NUMBER, RANK and DENSE_RANK functions in MySQL

Hughs

Answer 5

DENSE_RANK() function is available in MySQL version 8.0. So if you're using MySQL version 8.0 you can run this command,

SELECT name, DENSE_RANK() OVER ( ORDER BY value ) my_rank FROM table_name;

Wolverine

Answer 6

MySQL version 8 now has ROW_NUMBER. Documentation

EXAMPLE:

SELECT 
    ROW_NUMBER() OVER (ORDER BY s.Id) AS 'row_num', 
    s.product,
    s.title
FROM supplies AS S

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