IFS and INDEX/ MATCH EXCEL COUNTERPART IN SQL QUERY - sql

Question

My table looks like this
NAME BRAND REFERENCE COMMENTS <-Expected output
-------------------------------------------------
Gu Skirt 101128 Pants
Cci Pants 101127 Pants
Cha Skirt paired paired
Gu Pants 101128 Skirts
Nel Skirt nonpaired UNIQUE
Gir Pants 101188 Skirt
Baud Skirt dropped DROPPED
Le Pants paired PAIRED
Gir Skirt 101188 101178
Vis Socks blanks
Cci Skirts 101127 Skirts
I wonder what code to use to get the Comments result.
First reference in NUMBERS should be paired. If reference numbers match, return value should be the Brand counterpart.
If reference is in Character, they have to fall under if statements: IF character is Nonpaired return value should be unique, dropped for dropped and so on. If the reference is blanks no change.
Is this possible?
Thank you so much.

Answer 1

You can use common table expressions to break down the problem which can help with maintaining the code.
I didn't use lag/lead because you only have two rows in the pair, so numbering the rows and joining the table to itself felt quicker and easier to follow.
Here's the code I've used to answer and test your question;
create table #source
(
[NAME] varchar(200),
[BRAND] varchar(200),
[REFERENCE] varchar(200)
);
insert into #source values
('Gu','Skirt','101128'),
('Cci','Pants','101127'),
('Cha','Skirt','paired'),
('Gu','Pants','101128'),
('Nel','Skirt','nonpaired'),
('Gir','Pants','101188'),
('Baud','Skirt','dropped'),
('Le','Pants','paired'),
('Gir','Skirt','101188'),
('Vis','Socks',''),
('Cci','Skirts','101127'),
('Le','Socks','101188'),
('Uno','Socks','101101');
select * from #source;
with cteNumericRef as
(
select [NAME],[BRAND],[REFERENCE]
from #source
where ISNUMERIC([REFERENCE]) = 1
)
, cteCheckRow as
(
select [REFERENCE],
'CHECK' as [COMMENT]
from cteNumericRef
group by [REFERENCE]
having count(*) <> 2
)
, ctePairedRow as
(
select
num_ref.[NAME]
, num_ref.[BRAND]
, num_ref.[REFERENCE]
, row_number() over (partition by num_ref.[REFERENCE] order by num_ref.[NAME]) as [Pair_Num]
from cteNumericRef num_ref
left join cteCheckRow check_row
on check_row.[REFERENCE] = num_ref.[REFERENCE]
where check_row.[REFERENCE] is null
)
, cteTextRow as
(
select [NAME],[BRAND],[REFERENCE],
case [REFERENCE]
when 'paired' then 'PAIRED'
when 'nonpaired' then 'UNIQUE'
when 'dropped' then 'DROPPED'
when '' then ''
else 'CHECK' end as [COMMENT]
from #source
where ISNUMERIC([REFERENCE]) <> 1
)
select
left_row.[NAME]
, left_row.[BRAND]
, left_row.[REFERENCE]
, right_row.[BRAND] as [COMMENTS]
from ctePairedRow left_row
inner join ctePairedRow right_row
on left_row.[REFERENCE] = right_row.[REFERENCE]
and left_row.[Pair_Num] <> right_row.[Pair_Num]
union all
select
num_ref.[NAME]
, num_ref.[BRAND]
, num_ref.[REFERENCE]
, check_row.[COMMENT]
from cteNumericRef num_ref
inner join cteCheckRow check_row
on check_row.[REFERENCE] = num_ref.[REFERENCE]
union all
select
[NAME]
, [BRAND]
, [REFERENCE]
, [COMMENT]
from cteTextRow;
drop table #source

Answer 2

SELECT Name,
Brand,
Reference,
CASE WHEN Reference = 'Paired' THEN 'Paired'
WHEN Reference = 'nonpaired' THEN 'Unique'
WHEN Reference = 'dropped' THEN 'DROPPED'
WHEN Reference = ' ' THEN 'blanks'
WHEN Reference = Next_Ref AND rownum = 1 THEN next_brand
WHEN Reference = Prev_Ref AND rownum = 2 THEN prev_brand
END AS Comments
FROM
(
SELECT Name,
Brand,
Reference,
LAG( Reference, 1 )OVER PARTITION BY ( Reference ORDER BY Brand ) AS Prev_Ref,
LEAD( Reference, 1 )OVER PARTITION BY ( Reference ORDER BY Brand ) AS Next_Ref,
LAG( Brand, 1 ) OVER PARTITION BY ( Reference ORDER BY Brand ) AS Prev_Brand,
LEAD( Brand, 1 ) OVER PARTITION BY ( Reference ORDER BY Brand ) AS Next_Brand,
ROW_NUMBER( ) OVER PARTITION BY ( Reference ORDER BY Brand ) AS rownum
FROM Data
);