How to show recursive parentID in a single column in SQL - sql-server

Question

Here is the example structure of the table:
ID Name ParentID
-----------------------
1 Ancestor NULL
2 GrandFather 1
3 GrandMother 1
4 Child 3
I'm trying to write a query that would return
ID Name Family
----------------------------
1 Ancestor
2 GrandFather Ancestor
3 GrandMother Ancestor
4 Child Ancestor^GrandMother
The tricky part is that I want to show the family of all rows and in a top-down order.
If anyone can point me in the right direction, it would be appreciated :)
EDIT :: This is the real query, but it follows the same idea. it returns an error on line : marketparent.family + '^'+ t2.marketGroupName because it cant find marketparent
WITH marketparent ( marketGroupID,parentGroupID, marketGroupName,family)
AS
(
SELECT marketGroupID,
parentGroupID,
marketGroupName,
'' as family
FROM EVE.dbo.invMarketGroups
WHERE parentGroupID IS NULL
UNION ALL
SELECT t2.parentGroupID,
t2.marketGroupID,
t2.marketGroupName,
marketparent.family + '^'+ t2.marketGroupName
FROM EVE.dbo.invMarketGroups as t2
INNER JOIN marketparent as mp
ON mp.marketGroupID = t2.parentGroupID
)
-- Statement using the CTE
SELECT TOP 10 *
FROM marketparent;

Answer 1

You did not specify your DBMS, so I'm assuming PostgreSQL
WITH RECURSIVE fam_tree (id, name, parent, family) as
(
SELECT id,
name,
parentid,
''::text as family
FROM the_unknown_table
WHERE parent IS NULL
UNION ALL
SELECT t2.id,
t2.name,
t2.parentid,
fam_tree.family || '^' || t2.name
FROM the_unknown_table t2
INNER JOIN fam_tree ON fam_tree.id = t2.parentid
)
SELECT *
FROM fam_tree;
This is standard SQL (except for the ::text typecast) that should work with very few changes on most modern DBMS.
Edit:
For SQL Server you would need to replace the standard concatention character with Microsoft's non-standar + (and you need to remove the recursive keyword which is required by the standard but for some strange reason rejected by SQL Server)
WITH fam_tree (id, name, parent, family) as
(
SELECT id,
name,
parentid,
'' as family
FROM the_unknown_table
WHERE parent IS NULL
UNION ALL
SELECT t2.id,
t2.name,
t2.parentid,
fam_tree.family + '^' + t2.name
FROM the_unknown_table t2
INNER JOIN fam_tree ON fam_tree.id = t2.parentid
)
SELECT *
FROM fam_tree;

Answer 2

You can use a recursive Common Table Expression.
declare #T table
(
ID int,
Name nvarchar(15),
ParentID int
);
insert into #T values
(1, N'Ancestor', NULL),
(2, N'GrandFather', 1),
(3, N'GrandMother', 1),
(4, N'Child', 3);
with C as
(
select T.ID,
T.Name,
T.ParentID,
cast(N' ' as nvarchar(max)) as Family
from #T as T
where T.ParentID is null
union all
select T.ID,
T.Name,
T.ParentID,
C.Family+'^'+C.Name
from #T as T
inner join C
on T.ParentID = C.ID
)
select C.ID,
C.Name,
stuff(C.Family, 1, 2, '') as Family
from C;

Answer 3

select T.ID, T.Name, (select name from table where ID=T.ParentID)as Family
from table T