hi i need a query to do this
my table data
ID ParentID DATA
--------------------------------
1 -1 a
2 1 b
3 2 c
4 3 d
5 3 f
and what ineed a query that take a ID as parameter and return all recursively childs and Itself
parameter : (ID=2)
return must be :
ID ParentID DATA
--------------------------------
2 1 b
3 2 c
4 3 d
5 3 f
Try this:
;with temp as (
select id, parentId, data from t
where id = 2
union all
select t.id, t.parentId, t.data from t
join temp on temp.id = t.parentId
)
select * from temp
Fiddle here.
This should do it for you:
create table #temp
(
id int,
parentid int,
data varchar(1)
)
insert #temp (id, parentid, data) values (1, -1, 'a')
insert #temp (id, parentid, data) values (2,1, 'b')
insert #temp (id, parentid, data) values (3,2, 'c')
insert #temp (id, parentid, data) values (4,3, 'd')
insert #temp (id, parentid, data) values (5,3, 'f')
; with cte as (
select id, parentid, data, id as topparent
from #temp
union all
select child.id, child.parentid, child.data, parent.topparent
from #temp child
join cte parent
on parent.id = child.parentid
)
select id, parentid, data
from cte
where topparent = 2
drop table #temp
EDIT or you can put the WHERE clause inside the first select
create table #temp
(
id int,
parentid int,
data varchar(1)
)
insert #temp (id, parentid, data) values (1, -1, 'a')
insert #temp (id, parentid, data) values (2,1, 'b')
insert #temp (id, parentid, data) values (3,2, 'c')
insert #temp (id, parentid, data) values (4,3, 'd')
insert #temp (id, parentid, data) values (5,3, 'f')
; with cte as (
select id, parentid, data, id as topparent
from #temp
WHERE id = 2
union all
select child.id, child.parentid, child.data, parent.topparent
from #temp child
join cte parent
on parent.id = child.parentid
)
select id, parentid, data
from cte
drop table #temp
Results:
id parentid data
2 1 b
3 2 c
4 3 d
5 3 f
declare #ID int = 2;
with C as
(
select ID, ParentID, DATA
from YourTable
where ID = #ID
union all
select T.ID, T.ParentID, T.DATA
from YourTable as T
inner join C
on T.ParentID = C.ID
)
select ID, ParentID, DATA
from C
Try on SE-Data
try this.
select * from table where id= 2 or parentid = 2
Related
I was wondering if someone could help me.
I have a table that is like this ...
ID ParentID
1 0
2 1
3 2
4 3
5 4
What I want to do is write a recursive TSQL statement that will get all of my parents ID. So for example, if I pass 5 into the stored procedure it would return 4,3,2,1.
Does anyone know how to do this? It would be very much appreciated if someone could help!
This is an example how to achieve this using recursive CTE:
DECLARE #id INT
SET #id = 5
CREATE TABLE #tmp (id INT , ParentId INT)
INSERT INTO #tmp VALUES(1,0)
INSERT INTO #tmp VALUES(2,1)
INSERT INTO #tmp VALUES(3,2);
INSERT INTO #tmp VALUES(4, 3);
INSERT INTO #tmp VALUES(5,4);
WITH parent AS
(
SELECT id, parentId from #tmp WHERE id = #id
UNION ALL
SELECT t.id, t.parentId FROM parent
INNER JOIN #tmp t ON t.id = parent.parentid
)
SELECT id FROM parent
WHERE id <> #id;
--OR
WITH parent AS
(
SELECT tmp1.id, tmp1.parentId from #tmp AS tmp1
INNER JOIN #tmp AS tmp2 ON tmp1.id = tmp2.parentId
WHERE tmp2.id = #id
UNION ALL
SELECT t.id, t.parentId FROM parent
INNER JOIN #tmp t ON t.id = parent.parentid
)
SELECT id FROM parent
Use a recursive common table expression :
http://msdn.microsoft.com/en-us/library/ms186243.aspx
SELECT id, EmpNo
FROM EmployeesTable
EmpNo can be the same for 1 or more records in the results of the above query. I now want to add another column derived from EmpNo(lets call it EmpNo2) but only returning distinct values of EmpNo.
For example if the above query returns 100 records but there are 69 distinct EmpNo values and i modify the query to
SELECT id, EmpNo, Distinct EmpNo2
FROM EmployeesTable EmpNo
,
i want all the 100 rows to be returned but the last column EmpNo2 should return 69 distinct values of EmpNo field.
But as already know, using distinct in that way results into an error but i want to implement such functionality - and a subquery is not helping.
SAMPLE REQUIRED RESULTS
ID EmpNo EmpNo2
1 0T4/HR 0T4/HR
1 0T4/HR 2VP/E
1 0T4/HR xT9/67
1 0T4/HR
1 0T4/HR
2 2VP/E
2 2VP/E
2 2VP/E
2 2VP/E
2 2VP/E
3 XT9/67
3 XT9/67
3 xT9/67
3 XT9/67
How about:
Select id, empno, empno2
from employeestable left outer join (
SELECT min([id]) as minid
,[empno] empno2
FROM [EmployeesTable]
group by empno) etab2 on employeestable.id = etab2.minid
You're saying a subquery won't work, though - why not?
Your requirement is not clear and I also have very little information. Following is what you need. This can be even better but it is just a try.
declare #temp table
(
uniqueid int identity(1, 1),
id int,
empno varchar(50),
empno2 varchar(50)
)
insert into #temp select 1, '0T4/HR', null
insert into #temp select 1, '0T4/HR' , null
insert into #temp select 1 , '0T4/HR' , null
insert into #temp select 1, '0T4/HR' , null
insert into #temp select 1, '0T4/HR' , null
insert into #temp select 2, '2VP/E' , null
insert into #temp select 2, '2VP/E' , null
insert into #temp select 2, '2VP/E' , null
insert into #temp select 2, '2VP/E' , null
insert into #temp select 2, '2VP/E' , null
insert into #temp select 3, 'XT9/67' , null
insert into #temp select 3, 'XT9/67' , null
insert into #temp select 3, 'xT9/67' , null
insert into #temp select 3, 'XT9/67' , null
SELECT ROW_NUMBER() OVER (ORDER BY id) AS id, empno into #temp FROM #temp group by empno, id
update #temp set empno2 = t2.empno
from #temp t inner join #temp t2 on t.uniqueid = t2.id
select * from #temp
drop table #temp
Based on an existing table I used CTE recursive query to come up with following data. But failing to apply it a level further.
Data is as below
id name parentid
--------------------------
1 project 0
2 structure 1
3 path_1 2
4 path_2 2
5 path_3 2
6 path_4 3
7 path_5 4
8 path_6 5
I want to recursively form full paths from the above data. Means the recursion will give the following output.
FullPaths
-------------
Project
Project\Structure
Project\Structure\Path_1
Project\Structure\Path_2
Project\Structure\Path_3
Project\Structure\Path_1\path_4
Project\Structure\Path_2\path_5
Project\Structure\Path_3\path_6
Thanks
Here's an example CTE to do that:
declare #t table (id int, name varchar(max), parentid int)
insert into #t select 1, 'project' , 0
union all select 2, 'structure' , 1
union all select 3, 'path_1' , 2
union all select 4, 'path_2' , 2
union all select 5, 'path_3' , 2
union all select 6, 'path_4' , 3
union all select 7, 'path_5' , 4
union all select 8, 'path_6' , 5
; with CteAlias as (
select id, name, parentid
from #t t
where t.parentid = 0
union all
select t.id, parent.name + '\' + t.name, t.parentid
from #t t
inner join CteAlias parent on t.parentid = parent.id
)
select *
from CteAlias
Try something like this:
WITH Recursive AS
(
SELECT
ID,
CAST(PathName AS VARCHAR(500)) AS 'FullPaths',
1 AS 'Level'
FROM
dbo.YourTable
WHERE
ParentID = 0
UNION ALL
SELECT
tbl.ID,
CAST(r.FullPaths + '\' + tbl.PathName AS VARCHAR(500)) AS 'FullPaths',
r.Level + 1 AS 'Level'
FROM
dbo.YourTable tbl
INNER JOIN
Recursive r ON tbl.ParentID = r.ID
)
SELECT * FROM Recursive
ORDER BY Level, ID
Output:
ID FullPaths Level
1 project 1
2 project\structure 2
3 project\structure\path_1 3
4 project\structure\path_2 3
5 project\structure\path_3 3
6 project\structure\path_1\path_4 4
7 project\structure\path_2\path_5 4
8 project\structure\path_3\path_6 4
try this:
DECLARE #YourTable table (id int, nameof varchar(25), parentid int)
INSERT #YourTable VALUES (1,'project',0)
INSERT #YourTable VALUES (2,'structure',1)
INSERT #YourTable VALUES (3,'path_1',2)
INSERT #YourTable VALUES (4,'path_2',2)
INSERT #YourTable VALUES (5,'path_3',2)
INSERT #YourTable VALUES (6,'path_4',3)
INSERT #YourTable VALUES (7,'path_5',4)
INSERT #YourTable VALUES (8,'path_6',5)
;WITH Rec AS
(
SELECT
CONVERT(varchar(max),nameof) as nameof,id
FROM #YourTable
WHERE parentid=0
UNION ALL
SELECT
CONVERT(varchar(max),r.nameof+'\'+y.nameof), y.id
FROM #yourTable y
INNER jOIN Rec r ON y.parentid=r.id
)
select * from rec
output:
nameof
-----------------------------------------------
project
project\structure
project\structure\path_1
project\structure\path_2
project\structure\path_3
project\structure\path_3\path_6
project\structure\path_2\path_5
project\structure\path_1\path_4
(8 row(s) affected)
Something like
;WITH MyCTE AS
(
SELECT
name AS FullPaths, id
FROM
MyTable
WHERE
parentid = 0 /*Normally it'd be IS NULL with an FK linking the 2 columns*/
UNION ALL
SELECT
C.FullPaths + '\' + M.name, M.id
FROM
MyCTE C
JOIN
MyTable M ON M.parentid = C.id
)
SELECT FullPaths FROM MyCTE
You'll have to change the name of #test table I was using.
WITH cte(id, name, parentid) AS
(
SELECT id, convert(varchar(128), name), parentid
FROM #test
WHERE parentid = 0
UNION ALL
SELECT t.id, convert(varchar(128), c.name +'\'+t.name), t.parentid
FROM #test t
INNER JOIN cte c
ON c.id = t.parentid
)
SELECT name as FullPaths
FROM cte
order by id
I got a child table that contains 1 to n records linked to the master table via a MasterID column.
How can I select from the child table only the first 5 records for each MasterID?
Using Sql Server CTE and ROW_NUMBER you could try using
DECLARE #ParentTable TABLE(
ID INT
)
INSERT INTO #ParentTable SELECT 1
INSERT INTO #ParentTable SELECT 2
INSERT INTO #ParentTable SELECT 3
DECLARE #ChildTable TABLE(
ID INT,
ParentID INT
)
INSERT INTO #ChildTable SELECT 1, 1
INSERT INTO #ChildTable SELECT 2, 1
INSERT INTO #ChildTable SELECT 3, 1
INSERT INTO #ChildTable SELECT 4, 1
INSERT INTO #ChildTable SELECT 5, 1
INSERT INTO #ChildTable SELECT 6, 1
INSERT INTO #ChildTable SELECT 7, 1
INSERT INTO #ChildTable SELECT 8, 2
INSERT INTO #ChildTable SELECT 9, 2
INSERT INTO #ChildTable SELECT 10, 3
INSERT INTO #ChildTable SELECT 11, 3
;WITH RowNums AS(
SELECT pt.ID ParentID,
ct.ID ChildID,
ROW_NUMBER() OVER (PARTITION BY pt.ID ORDER BY ct.ID) RowNum
FROM #ParentTable pt INNER JOIN
#ChildTable ct ON pt.ID = ct.ParentID
)
SELECT ParentID,
ChildID
FROM RowNums
WHERE RowNum <= 5
Try a regular join where the constraint is a subquery pulling the TOP 5 from the child table. In untested pseudocode:
SELECT A.MasterID, B.*
FROM MasterTable A
JOIN ChildTable B
ON A.MasterID = B.MasterID
AND B.ChildID IN (SELECT Top 5 ChildID FROM ChildTable
WHERE MasterID = A.MasterID ORDER BY Whatever)
Suppose I have a recursive table (e.g. employees with managers) and a list of size 0..n of ids. How can I find the lowest common parent for these ids?
For example, if my table looks like this:
Id | ParentId
---|---------
1 | NULL
2 | 1
3 | 1
4 | 2
5 | 2
6 | 3
7 | 3
8 | 7
Then the following sets of ids lead to the following results (the first one is a corner case):
[] => 1 (or NULL, doesn't really matter)
[1] => 1
[2] => 2
[1,8] => 1
[4,5] => 2
[4,6] => 1
[6,7,8] => 3
How to do this?
EDIT: Note that parent isn't the correct term in all cases. It's the lowest common node in all paths up the tree. The lowest common node can also be a node itself (for example in the case [1,8] => 1, node 1 is not a parent of node 1 but node 1 itself).
Kind regards,
Ronald
Here's one way of doing it; it uses a recursive CTE to find the ancestry of a node, and uses "CROSS APPLY" over the input values to get the common ancestry; you just change the values in #ids (table variable):
----------------------------------------- SETUP
CREATE TABLE MyData (
Id int NOT NULL,
ParentId int NULL)
INSERT MyData VALUES (1,NULL)
INSERT MyData VALUES (2,1)
INSERT MyData VALUES (3,1)
INSERT MyData VALUES (4,2)
INSERT MyData VALUES (5,2)
INSERT MyData VALUES (6,3)
INSERT MyData VALUES (7,3)
INSERT MyData VALUES (8,7)
GO
CREATE FUNCTION AncestorsUdf (#Id int)
RETURNS TABLE
AS
RETURN (
WITH Ancestors (Id, ParentId)
AS (
SELECT Id, ParentId
FROM MyData
WHERE Id = #Id
UNION ALL
SELECT md.Id, md.ParentId
FROM MyData md
INNER JOIN Ancestors a
ON md.Id = a.ParentId
)
SELECT Id FROM Ancestors
);
GO
----------------------------------------- ACTUAL QUERY
DECLARE #ids TABLE (Id int NOT NULL)
DECLARE #Count int
-- your data (perhaps via a "split" udf)
INSERT #ids VALUES (6)
INSERT #ids VALUES (7)
INSERT #ids VALUES (8)
SELECT #Count = COUNT(1) FROM #ids
;
SELECT TOP 1 a.Id
FROM #ids
CROSS APPLY AncestorsUdf(Id) AS a
GROUP BY a.Id
HAVING COUNT(1) = #Count
ORDER BY a.ID DESC
Update if the nodes aren't strictly ascending:
CREATE FUNCTION AncestorsUdf (#Id int)
RETURNS #result TABLE (Id int, [Level] int)
AS
BEGIN
WITH Ancestors (Id, ParentId, RelLevel)
AS (
SELECT Id, ParentId, 0
FROM MyData
WHERE Id = #Id
UNION ALL
SELECT md.Id, md.ParentId, a.RelLevel - 1
FROM MyData md
INNER JOIN Ancestors a
ON md.Id = a.ParentId
)
INSERT #result
SELECT Id, RelLevel FROM Ancestors
DECLARE #Min int
SELECT #Min = MIN([Level]) FROM #result
UPDATE #result SET [Level] = [Level] - #Min
RETURN
END
GO
and
SELECT TOP 1 a.Id
FROM #ids
CROSS APPLY AncestorsUdf(Id) AS a
GROUP BY a.Id, a.[Level]
HAVING COUNT(1) = #Count
ORDER BY a.[Level] DESC
After doing some thinking and some hints in the right direction from Marc's answer (thanks), I came up with another solution myself:
DECLARE #parentChild TABLE (Id INT NOT NULL, ParentId INT NULL);
INSERT INTO #parentChild VALUES (1, NULL);
INSERT INTO #parentChild VALUES (2, 1);
INSERT INTO #parentChild VALUES (3, 1);
INSERT INTO #parentChild VALUES (4, 2);
INSERT INTO #parentChild VALUES (5, 2);
INSERT INTO #parentChild VALUES (6, 3);
INSERT INTO #parentChild VALUES (7, 3);
INSERT INTO #parentChild VALUES (8, 7);
DECLARE #ids TABLE (Id INT NOT NULL);
INSERT INTO #ids VALUES (6);
INSERT INTO #ids VALUES (7);
INSERT INTO #ids VALUES (8);
DECLARE #count INT;
SELECT #count = COUNT(1) FROM #ids;
WITH Nodes(Id, ParentId, Depth) AS
(
-- Start from every node in the #ids collection.
SELECT pc.Id , pc.ParentId , 0 AS DEPTH
FROM #parentChild pc
JOIN #ids i ON pc.Id = i.Id
UNION ALL
-- Recursively find parent nodes for each starting node.
SELECT pc.Id , pc.ParentId , n.Depth - 1
FROM #parentChild pc
JOIN Nodes n ON pc.Id = n.ParentId
)
SELECT n.Id
FROM Nodes n
GROUP BY n.Id
HAVING COUNT(n.Id) = #count
ORDER BY MIN(n.Depth) DESC
It now returns the entire path from the lowest common parent to the root node but that is a matter of adding a TOP 1 to the select.