Re: Real life SQL Brain teaser

[Charles Wilt <charles.wilt@xxxxxxxxx>]

-- get a numbered list of customers with each distinct (type,code)
with list as (select customer, type, code, row_number() over(partition by
type, code order by customer asc) as rowNbr
           from mytbl)
select customer, type, code
from list
where rowNbr = 1
order by customer, type, code;

Charles

On Wed, Nov 18, 2020 at 11:07 AM Dave <dfx1@xxxxxxxxxxxxxx> wrote:

> Hi,
>
>
>
> Before I start writing a program, I was wondering if SQL could offer an
> easier solution. I've been looking at using rank and over functions, but I
> can't see it! :
>
> In my table below there are 4 customers but only 3 distinct combinations of
> Type and Code.
>
> Customer           Type      Code
>
> 1                             T1           C1
>
> 1                             T1           C2
>
> 2                             T2           C3
>
> 2                             T2           C4
>
> 3                             T5           C1
>
> 4                             T1           C1
>
> 4                             T1           C2
>
>
>
> From this table, can I create the following table that contains each
> combination of Type and Code only once ?
>
> combination      Type      Code
>
> 1                             T1           C1
>
> 1                             T1           C2
>
> 2                             T2           C3
>
> 2                             T2           C4
>
> 3                             T5           C1
>
>
>
> TIA !
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