Hierarchical data with CTE - sql

Question

I am sorry if the answer has been posted already, but I was not able to find the answer even after searching.
I have the following table
CREATE TABLE [dbo].[emp](
[id] [int] NOT NULL,
[name] [varchar](20) NULL,
[mgrid] [int] NULL
) ON [PRIMARY]
With data
INSERT [dbo].[emp] ([id], [name], [mgrid]) VALUES (1, N'a', 0)
INSERT [dbo].[emp] ([id], [name], [mgrid]) VALUES (2, N'a1', 1)
INSERT [dbo].[emp] ([id], [name], [mgrid]) VALUES (3, N'a11', 2)
INSERT [dbo].[emp] ([id], [name], [mgrid]) VALUES (4, N'a12', 2)
INSERT [dbo].[emp] ([id], [name], [mgrid]) VALUES (5, N'a13', 2)
INSERT [dbo].[emp] ([id], [name], [mgrid]) VALUES (6, N'a2', 1)
INSERT [dbo].[emp] ([id], [name], [mgrid]) VALUES (7, N'a3', 1)
INSERT [dbo].[emp] ([id], [name], [mgrid]) VALUES (8, N'a31', 7)
INSERT [dbo].[emp] ([id], [name], [mgrid]) VALUES (9, N'a32', 7)
INSERT [dbo].[emp] ([id], [name], [mgrid]) VALUES (10, N'b', 0)
INSERT [dbo].[emp] ([id], [name], [mgrid]) VALUES (11, N'b1', 10)
INSERT [dbo].[emp] ([id], [name], [mgrid]) VALUES (12, N'b2', 10)
And I would like the following output
a
a1
a11
a12
a13
a2
a3
a31
a32
b
b1
b2
Is this possible in SQL Server?

Answer 1

SQLFiddle demo
You can use ' ' instead of '+' in the last line to pad a string.
with t as
(
select id,name,mgrid,1 as level,cast(name as varchar(max)) as path
from emp where mgrid=0
union all
select emp.id,emp.name,emp.mgrid, t.level+1 as level,
t.path+cast(emp.name as varchar(max)) as path
from emp
join t on emp.mgrid=t.id
)
select replicate('+', level)+name from t order by path

Answer 2

with CTE as
(
select *
, level = 1
from emp
where mgrid = 0
union all
select emp.id,
name = cast(space((level) * 3) + emp.name as varchar(20)),
emp.mgrid,
level = level + 1
from emp
inner join CTE on CTE.id = emp.mgrid
)
select name
from CTE
order by ltrim(name)

Answer 3

Query:
DECLARE #temp TABLE
(
[id] [int] NOT NULL,
[name] [varchar](20) NULL,
[mgrid] [int] NULL
)
INSERT INTO #temp ([id], [name], [mgrid])
VALUES
(1, N'a', 0), (2, N'a1', 1),
(3, N'a11', 2), (4, N'a12', 2),
(5, N'a13', 2), (6, N'a2', 1),
(7, N'a3', 1), (8, N'a31', 7),
(9, N'a32', 7), (10, N'b', 0),
(11, N'b1', 10), (12, N'b2', 10)
DECLARE #out VARCHAR(MAX) = ''
;WITH cte AS
(
SELECT *, Lvl = 0, nn = CAST(name AS VARCHAR(MAX))
FROM #temp
WHERE mgrid = 0
UNION ALL
SELECT t.*, c.Lvl + 1, nn = CAST(REPLICATE(' ', c.Lvl + 1) + t.name AS VARCHAR(MAX))
FROM #temp t
JOIN cte c ON c.id = t.mgrid
)
SELECT #out = (
SELECT nn + CHAR(13)
FROM cte
ORDER BY LTRIM(nn)
FOR XML PATH(''), TYPE).value('.', 'NVARCHAR(MAX)')
PRINT #out
Output:
a
a1
a11
a12
a13
a2
a3
a31
a32
b
b1
b2

Answer 4

You can use CTE (Comnon table expression to achieve this)
check this sample code:
declare #emp table(
[id] [int] NOT NULL,
[name] [varchar](20) NULL,
[mgrid] [int] NULL
)
INSERT #emp ([id], [name], [mgrid]) VALUES (1, N'a', 0)
INSERT #emp ([id], [name], [mgrid]) VALUES (2, N'a1', 1)
INSERT #emp ([id], [name], [mgrid]) VALUES (3, N'a11', 2)
INSERT #emp ([id], [name], [mgrid]) VALUES (4, N'a12', 2)
INSERT #emp ([id], [name], [mgrid]) VALUES (5, N'a13', 2)
INSERT #emp ([id], [name], [mgrid]) VALUES (6, N'a2', 1)
INSERT #emp ([id], [name], [mgrid]) VALUES (7, N'a3', 1)
INSERT #emp ([id], [name], [mgrid]) VALUES (8, N'a31', 7)
INSERT #emp ([id], [name], [mgrid]) VALUES (9, N'a32', 7)
INSERT #emp ([id], [name], [mgrid]) VALUES (10, N'b', 0)
INSERT #emp ([id], [name], [mgrid]) VALUES (11, N'b1', 10)
INSERT #emp ([id], [name], [mgrid]) VALUES (12, N'b2', 10);
with cte (id,name, MGRID) as
(
select id, name,MGRID
from #emp
union all
select c.id, c.name, c.MGRID
from #emp c
inner join cte p
on c.mgrid = P.id
)
SELECT Distinct * FROM CTE

Answer 5

WITH RCTE AS
(
SELECT id, name, mgrid, CAST('' AS NVARCHAR(MAX)) AS blanks , CAST(name AS NVARCHAR(MAX)) AS ordr
FROM dbo.emp WHERE mgrid = 0
UNION ALL
SELECT e.id, e.name, e.mgrid, blanks + ' ' AS blanks, ordr + e.name AS ordr
FROM dbo.emp e
INNER JOIN RCTE r ON e.mgrid = r.id
)
SELECT blanks + name FROM RCTE
ORDER BY ordr