Sami

Great @McNets that's awesome. Thank you so much for your time & effort.

Until now, I can't came up with a solution. Thanks for pointing, I'll work more to learn more.

@McNets Nope, that won't reset the Seq, see the expected results ^

Thanks for you both @PaulWhite & @McNets

It seems there is no solution, even if we add an identity column to the T table

Thnx @PaulWhite

@McNets As you can see there is no order there and there is no column to determine the order

@PaulWhite There is no reason, expect I believe I'll get answers here too (quick one) and it's just for learning, no matter if I got answers or not

@McNets Nope, It's a seq, if val = 2 then 0, else start the seq again from 1

Note: There is no other columns in the table T except Val column

+-----+-----+
| Val | Seq |
+-----+-----+
|   2 |   0 |
|   2 |   0 |
|   1 |   1 |
|   1 |   2 |
|   1 |   3 |
|   2 |   0 |
|   1 |   1 |
|   2 |   0 |
|   1 |   1 |
|   1 |   2 |
+-----+-----+

Expected results:

Online Demo

Anyone can help please to get the expected results?

Hey @PaulWhite

o/

I did in a comment ;)

Yup, but I won't guide someone to a wrong way

but not STRING_AGG(Tag, ',')

Something like, STRING_AGG(Tag, '","')

SO, used that for the tags of the question I think

Ugh, Such a talent

@TomV SO always confuse me as such users do not point the OPs for the real problem

@ypercubeᵀᴹ Thnx

@ypercubeᵀᴹ in Oracle is?

@nuttyaboutnatty That's the full one

ServerName.DatabaseName.SchemaName.TableName

eh? a table name starts with a number?

Morning guys!

@War :D

Sure, it's already deleted Paul

Yeah, that's right

@PaulWhite Hey, hmmm maybe I'm wrong let me check

For the rows -> stackoverflow.com/questions/56898132/…

It's all up to the optimizer

that makes the "Why second query doesn't use index? Because indexed column is wrapped in a function which prevents SQL Server from using index." in the answer wrong

@AndriyM Yeah, I just want to understand

eg: SELECT [Date] FROM Exams or SELECT 1 FROM Exams

Even so if we remove * the optimizer will decide to use the index

demo

None of the queries will use the index, instead it's a full table scan (tested on db<>fiddle)

Both queries will use the index (tested on SQL Server 2008)

From this question on SO (SQL Server) don't you think guys that the right answer is "it depends on the optimizer"?

Morning o/

@Lamak I don't see you there much those days, think you 'll like to give that a chance :)

Afternoon

@PaulWhite I just reference ya here and if you have any comment about the A please do.

Morning!