TSQL create ragged hierarchy from flat structure - sql

Question

Consider this table:
declare #table as table (
GL_Group_Code varchar(8),
GL_Branch_Code varchar(8),
Account_Number varchar(4),
GL_Centre_Number varchar(6)
)
insert into #table
select '0100', '0110', '1200', 'S10118' union
select '0100', '0110', '1580', 'S16053' union
select '0200', '0210', '2050', '200049' union
select '0200', '0210', '2050', '782844'
The desired outcome is a parent child relationship across the four source columns into:
declare #table_hier as table (
Parent_ID varchar(8),
Item_ID varchar(8)
)
With a relationship order of column 1,2,3,4 the result for the first row from the source table would look like:
null 0100
0100 0110
0110 1200
1200 S10118
The second row would be:
null 0100
0100 0110
0110 1580
1580 S16053
The relationship order can vary: 1,2,4,3 or 3,4 or 1,3,4
I'm thinking recursive CTE however late on a Friday I could do with little help.

Answer 1

IF you can have id in your table and use table variable to store columns you want to get, you can do this:
declare #ord table (id int)
insert into #ord
values (1), (2), (4)
;with cte as (
select
t.id,
c.value,
row_number() over(partition by t.id order by c.id) as rn
from #table as t
cross apply (
values
(1, t.GL_Group_Code),
(2, t.GL_Branch_Code),
(3, t.Account_Number),
(4, t.GL_Centre_Number)
) as c(id, value)
where
exists (select * from #ord as o where o.id = c.id)
)
insert into #table_hier
select
c1.value as Parent_ID, c2.value as Item_ID
from cte as c1
inner join cte as c2 on c2.rn = c1.rn + 1 and c2.id = c1.id
order by c1.rn
insert into #table_hier
select null, t.Parent_ID
from #table_hier as t
where
not exists
(
select *
from #table_hier as t2
where t2.Item_ID = t.Parent_ID
)
select * from #table_hier
sql fiddle demo
Or if you can store your data in the tables or temporary tables, you can use dynamic SQL solution:
declare #ord table (id int)
declare #stmt nvarchar(max)
insert into #ord
values (1), (2), (4)
;with cte as (
select c.name, row_number() over(order by c.colid) as rn
from sys.syscolumns as c
where
c.id = object_id('dbo.table1') and
exists (select * from #ord as o where o.id = c.colid)
)
select #stmt =
isnull(#stmt + ', ', '') +
'(' + c1.name + ', ' + c2.name + ')'
from cte as c1
inner join cte as c2 on c2.rn = c1.rn + 1
order by c1.rn
select #stmt = '
insert into table_hier1
select C.Parent_ID, C.Item_ID
from table1 as t
cross apply (
values ' + #stmt + '
) as C(Parent_ID, Item_ID)
'
exec sp_executesql
#stmt = #stmt
insert into table_hier1
select null, t.Parent_ID
from table_hier1 as t
where
not exists
(
select *
from table_hier1 as t2
where t2.Item_ID = t.Parent_ID
)
select * from table_hier1
sql fiddle demo

Answer 2

try something like this
declare #table as table (
GL_Group_Code varchar(8),
GL_Branch_Code varchar(8),
Account_Number varchar(4),
GL_Centre_Number varchar(6)
)
insert into #table
select '0100', '0110', '1200', 'S10118' union
select '0100', '0110', '1580', 'S16053' union
select '0200', '0210', '2050', '200049' union
select '0200', '0210', '2050', '782844'
declare #table_hier as table (
Parent_ID varchar(8),
Item_ID varchar(8)
)
DECLARE #RelatonShip VARCHAR(4)
SET #RelatonShip = '134'
IF #RelatonShip = '1234'
BEGIN
INSERT INTO #table_hier ( Parent_ID, Item_ID )
SELECT GL_Group_Code, GL_Branch_Code FROM #table
UNION ALL SELECT GL_Branch_Code, Account_Number FROM #Table
UNION ALL SELECT Account_Number, GL_Centre_Number FROM #table
END
IF #RelatonShip = '1243'
BEGIN
INSERT INTO #table_hier ( Parent_ID, Item_ID )
SELECT GL_Group_Code, GL_Branch_Code FROM #table
UNION ALL SELECT GL_Branch_Code, GL_Centre_Number FROM #Table
UNION ALL SELECT GL_Centre_Number, Account_Number FROM #table
END
IF #RelatonShip = '34'
BEGIN
INSERT INTO #table_hier ( Parent_ID, Item_ID )
SELECT Account_Number, GL_Centre_Number FROM #table
END
IF #RelatonShip = '134'
BEGIN
INSERT INTO #table_hier ( Parent_ID, Item_ID )
SELECT GL_Group_Code, Account_Number FROM #table
UNION ALL SELECT Account_Number, GL_Centre_Number FROM #table
END
SELECT * FROM #table_hier