Suppose the following DB setup in SQL Server 2014:

DECLARE @MATERIAL TABLE (ID int, CODE varchar(30));

INSERT @MATERIAL (ID, CODE) VALUES
(1, 'D3033MBBY'),
(2, 'D3033MBTY'),
(3, '011130-01'),
(4, '011130-04C'),
(5, '021002'),
(6, '021017-B'),
(7, '021134-01'),
(8, '021135-01'),
(9, '021955-01'),
(10, '3LS91101-550'),
(11, 'D3049MBRB'),
(12, 'EF0118'),
(13, 'FV8130'),
(14, 'FY7009'),
(15, 'H05802'),
(16, 'D3033MRTE');

DECLARE @SUBSTITUTE TABLE (ID int, ITEID int, SUBSTITUTECODE varchar(100));

INSERT @SUBSTITUTE (ID, ITEID, SUBSTITUTECODE) VALUES
(5232, 1, '191045762418'),
(5442, 2, '191045762418'),
(6435, 3, '5206432380030'),
(6573, 4, '5206432380030'),
(6582, 5, '5206432357131'),
(6683, 6, '5206432369486'),
(7332, 7, '5206432380610'),
(7482, 8, '5206432380818'),
(7721, 9, '5206432346029'),
(7831, 10, '5205172116350'),
(8034, 11, '191045480992'),
(8184, 12, '4061622759543'),
(8284, 13, '4062058577497'),
(8573, 14, '4064039588089'),
(9438, 15, '4064048672519'),
(9746, 16, '191045762418');

SELECT sub.SUBSTITUTECODE
FROM @SUBSTITUTE AS sub
INNER JOIN @MATERIAL AS prod ON prod.ID = sub.ITEID
GROUP BY sub.SUBSTITUTECODE
HAVING COUNT(sub.SUBSTITUTECODE) > 1;

I would like to create a query that would produce the following resultset:

In other words, I'd like to get a comma-separated set of CODEs in @MATERIAL where there are duplicate SUBSTITUTECODE references for those records in table @SUBSTITUTE

Indirectly, I can find the CODEs that correspond to those duplicate SUBSTITUTECODEs with the following query:

SELECT prod.CODE, sub.SUBSTITUTECODE
FROM @SUBSTITUTE AS sub
INNER JOIN @MATERIAL AS prod ON prod.ID = sub.ITEID
WHERE sub.SUBSTITUTECODE IN (SELECT sub.SUBSTITUTECODE
    FROM @SUBSTITUTE AS sub
    INNER JOIN @MATERIAL AS prod ON prod.ID = sub.ITEID
    GROUP BY sub.SUBSTITUTECODE
    HAVING COUNT(sub.SUBSTITUTECODE) > 1)

Working fiddle for the above case can be found here.

Please note that the full case of this scenario runs on SQL Server 2014.

TIA

CodePudding user response：

Nice starting fiddle, thanks! If we just take what you already have and put it in a CTE, we can write a standard string aggregation around it:

;WITH subs AS 
(
  SELECT prod.CODE, sub.SUBSTITUTECODE
  FROM @SUBSTITUTE AS sub
  INNER JOIN @MATERIAL AS prod ON prod.ID = sub.ITEID
  WHERE sub.SUBSTITUTECODE IN (SELECT sub.SUBSTITUTECODE
    FROM @SUBSTITUTE AS sub
    INNER JOIN @MATERIAL AS prod ON prod.ID = sub.ITEID
    GROUP BY sub.SUBSTITUTECODE
    HAVING COUNT(sub.SUBSTITUTECODE) > 1)
)
SELECT CODES = STUFF((SELECT ','   CODE 
  FROM subs AS s2 WHERE s2.SUBSTITUTECODE = subs.SUBSTITUTECODE
  FOR XML PATH, TYPE).value(N'.[1]', N'nvarchar(max)'),1,1,''),
    SUBSTITUTECODE FROM subs
  GROUP BY SUBSTITUTECODE;

• Example db<>fiddle

But we can simplify this code slightly, most importantly to avoid referencing both tables twice, like this:

;WITH subs AS
(
  SELECT s.ITEID, s.SUBSTITUTECODE, m.CODE, 
    c = COUNT(*) OVER (PARTITION BY s.SUBSTITUTECODE)
  FROM @SUBSTITUTE AS s
  INNER JOIN @MATERIAL AS m
  ON m.ID = s.ITEID
)
SELECT CODES = STUFF((SELECT ','   CODE
  FROM subs AS s2 WHERE s2.SUBSTITUTECODE = subs.SUBSTITUTECODE
  FOR XML PATH, TYPE).value(N'.[1]', N'nvarchar(max)'),1,1,''),
    SUBSTITUTECODE
  FROM subs 
  WHERE c > 1 
  GROUP BY SUBSTITUTECODE;

• Example db<>fiddle

Note that on more modern versions of SQL Server (2017 ), STRING_AGG() makes this much easier:

SELECT CODES = STRING_AGG(m.CODE, ','), s.SUBSTITUTECODE
  FROM @SUBSTITUTE AS s
  INNER JOIN @MATERIAL AS m
  ON m.ID = s.ITEID
  GROUP BY s.SUBSTITUTECODE
  HAVING COUNT(*) > 1;

• Example db<>fiddle

CodePudding user response：

Since you are using SQL Server 2014, you can't use STRING_AGG()

Here is the solution using FOR XML PATH

WITH CTE AS
(
    SELECT prod.CODE, sub.SUBSTITUTECODE, 
           c = COUNT(*) OVER (PARTITION BY sub.SUBSTITUTECODE)
    FROM   @SUBSTITUTE AS sub
           INNER JOIN @MATERIAL AS prod ON prod.ID = sub.ITEID
),
CTE2 AS
(
    SELECT *
    FROM   CTE
    WHERE  c > 1
)
SELECT STUFF((SELECT ','   CODE 
              FROM CTE2 x 
              WHERE x.SUBSTITUTECODE = c.SUBSTITUTECODE 
              FOR XML PATH('')), 1, 1, ''),
       SUBSTITUTECODE
FROM   CTE2 c
GROUP BY SUBSTITUTECODE