How to create a single string in SQL, based on Hierarchical Data - CTE and XML? - sql

Question

I have a database table storing stock locations for various products.
One part number can have several Departments, each department can have several racks and so on (shelves and then rows).
I need to concatenate this information to fit the dataset on label (on a single line).
To retrieve the dataset my query is as follows.
select d.Department_Name, r.Rack_Name, s.Shelf_Name, rw.Row_Name from Part_Locator l
join Part_Numbers p
on l.Part_Id=p.Part_Id
join PL_Departments d
on l.Department_Id=d.Department_Id
join PL_Racks r
on l.Rack_Id=r.Rack_Id
join PL_Shelfs s
on l.Shelf_Id=s.Shelf_Id
join PL_Rows rw
on l.Row_Id=rw.Row_Id
where p.Part_Number='1BODY000997'
Results are as follows:
I can make a nested look to build a string, but I believe a combination of recursive CTE, Stuff and XML could so the same for me. So far I can find many examples, but none that I can understand well enough to make them work together application.
The desired output is as follows:
Assembly - Rack IA-10 - Shelf A - Row 1,2,3,4,5,6 - Shelf B - Row 1,2,3,4,5,6 - Shelf C - Row 1,2,3,4,5,6
I am not opposed to changing that format as long as it reads logically. Also please note there can multiple departments.
Any help to get me going in the right direction would be great.
Thanks in advance!
I was able to get this working using cursor. I also created a view to remove the joins from the query, much easier to read.
DECLARE
#partnumber varchar(50)='1BODY000997', #dept varchar(50), #rack varchar(50), #shelf varchar(50), #row varchar(50), #text varchar(500)='';
DECLARE department_cursor CURSOR FOR
SELECT DISTINCT Department_Name FROM Part_Locations WHERE Part_Number=#partnumber
OPEN department_cursor;
FETCH NEXT FROM department_cursor INTO #dept;
WHILE ##FETCH_STATUS = 0
BEGIN
SET #text=#text+CAST(#dept as varchar(50))+' - ';
DECLARE rack_cursor CURSOR FOR
SELECT DISTINCT Rack_Name FROM Part_Locations WHERE Part_Number=#partnumber AND Department_Name=#dept
OPEN rack_cursor;
FETCH NEXT FROM rack_cursor INTO #rack
WHILE ##FETCH_STATUS = 0
BEGIN
SET #text=#text+'Rack:'+CAST(#rack as varchar(50))+' - ';
DECLARE shelf_cursor CURSOR FOR
SELECT DISTINCT Shelf_Name FROM Part_Locations WHERE Part_Number=#partnumber AND Department_Name=#dept AND Rack_Name=#rack
OPEN shelf_cursor;
FETCH NEXT FROM shelf_cursor INTO #shelf
WHILE ##FETCH_STATUS = 0
BEGIN
SET #text=#text+'Shelf:'+CAST(#shelf as varchar(50))+' (Row ';
SET #text=#text+(SELECT abc=STUFF((SELECT DISTINCT ',' + Row_Name FROM Part_Locations WHERE Part_Number=#partnumber AND Department_Name=#dept AND Rack_Name=#rack AND Shelf_Name=#shelf FOR XML PATH ('')), 1, 1, ''))
SET #text=#text+') ';
FETCH NEXT FROM shelf_cursor INTO #shelf
END;
CLOSE shelf_cursor;
DEALLOCATE shelf_cursor;
FETCH NEXT FROM rack_cursor INTO #rack
END;
CLOSE rack_cursor;
DEALLOCATE rack_cursor;
FETCH NEXT FROM department_cursor INTO #dept;
END
CLOSE department_cursor;
DEALLOCATE department_cursor;
PRINT (#text)
this gives me good output of..
Assembly - Rack:IA-10 - Shelf:A (Row 1,2,3,4,5,6) Shelf:B (Row 1,2,3,4,5,6) Shelf:C (Row 1,2,3,4,5,6)

Answer 1

As mentioned, you could do a cte, or you could do a running field (similar to running total) , or xml path. Actually, forget the running field, too hard. Below are two examples , one with xml, followed by a cte. I used in that link I sent earlier to the the xml path. Due to the complexity, I needed to do two xml paths ( first one into a temp table)
Note that I created a table (ITEMS) and put your results into it ...
SELECT DISTINCT i.Dept, i.rack, i.shelf,
stuff( ( select ',' + i2.rowname
from ITEMS i2
where i2.Dept = i.Dept and
i2.rack = i.rack and
i2.shelf =i.shelf
FOR XML PATH('')),1,1,'') as RownumbersCommaSeparated
INTO #T1
FROM ITEMS i
SELECT
stuff( ( select ' ' + T.Dept + ' Rack ' + T.rack + ' Shelf ' + T.shelf + ' Rows ' + T.RownumbersCommaSeparated
from #T1 T
FOR XML PATH('')),1,1,'' ) as DesiredOutput
The common table expression is a bit longer ! There are TWO recursions ...
;
WITH
CTE0 AS
(
SELECT i.*,
ROW_NUMBER() OVER(ORDER BY i.Dept,i.rack,i.shelf, i.rowname) recordnumber,
RANK() OVER ( ORDER BY i.Dept,i.rack,i.shelf) Parent,
RANK() OVER (PARTITION BY i.Dept,i.rack,i.shelf ORDER BY i.Dept,i.rack,i.shelf,i.rowname) rowidForeachParent
FROM ITEMS i
),
CTE1 AS
( SELECT
i.Parent,
i.Dept + ' Rack ' +
i.rack + ' Shelf ' +
i.shelf + ' Rows ' as CoreData,
MAX(i.rowidforeachparent) maxrowidforeachparent
FROM cte0 i
group by i.Parent, i.Dept, i.rack, i.shelf
),
CTE2 AS
(
SELECT
i1.Parent,
i1.maxrowidforeachparent,
CAST( i1.CoreData + ',' + i0.rowname AS varchar(MAX) ) as outputX,
i0.rowidForeachParent
FROM cte1 i1
join cte0 i0 on
i0.Parent = i1.Parent AND
I0.rowidForeachParent = 1
UNION ALL
SELECT
i1.Parent,
i1.maxrowidforeachparent,
i1.outputX + ',' + i0.rowname,
i0.rowidForeachParent
FROM cte2 i1
join cte0 i0 on
i0.Parent = i1.Parent AND
I0.rowidForeachParent = I1.rowidForeachParent+1
) ,
CTE3 AS
(
SELECT i.outputX ,
ROW_NUMBER() OVER (ORDER BY Parent) ParentId
FROM cte2 i
where i.rowidForeachParent = i.maxrowidforeachparent
),
CTE4 AS
(
SELECT outputX, i3.ParentId FROM CTE3 i3
where i3.ParentId = 1
UNION ALL
SELECT i4.outputX + ' ' + i3.outputX, i3.ParentId FROM CTE3 i3
join CTE4 i4 on i3.ParentId = i4.ParentId + 1
)
select top 1 * from cte4 order by ParentId desc