SQL QUERY 中的 IFS 和 INDEX/ MATCH EXCEL 对应部分

Question

我的桌子是这样的

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

我想知道使用什么代码来获得Comments 结果。

NUMBERS 中的第一个引用应该配对。如果参考编号匹配，则返回值应为 Brand 对应值。

如果引用在Character 中，则它们必须属于 if 语句：IF 字符是非配对返回值应该是唯一的，丢弃表示丢弃等等。如果引用为空白，则没有变化。

这可能吗？

非常感谢。

Answer 1

您可以使用公用表表达式来分解问题，这有助于维护代码。

我没有使用滞后/领先，因为这对中只有两行，因此对行进行编号并将表格连接到自身感觉更快，更容易遵循。

这是我用来回答和测试您的问题的代码；

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
     );