Find root in a database tree-structured table using SQL - sql

I have the following DB table describing a Bill Of Materials(BOM), basically a tree-structure:
Part(PartId, ParentId, PartName)
The Parts with ParentId = 0 are finished product, meaning they do not compose any other product.
Now given a PartId I would like to know to which products it belongs by using plain SQL (MS SQL Server) or LINQ lambda

Try the following:
;WITH CTE AS
(
SELECT PartId, ParentId
FROM Part
WHERE PartId = #PartId
UNION ALL
SELECT B.PartId, B.ParentId
FROM CTE A
INNER JOIN #Part B
ON A.ParentId = B.PartId
)
SELECT DISTINCT PartId
FROM CTE
WHERE ParentId = 0

Related

SQL Server: Query for products with matching tags

I have been pondering over this for the past few hours but I cannot find a solution.
I have a products in a table, tags in another table and a product/tag link table.
Now I want to retrieve all products which have the same tags as a certain product.
Here are the tables (simplified):
PRODUCT:
id varchar(36) (primary key)
Name varchar(50)
TAG:
id varchar(36) (primary key)
Name varchar(50)
PRODUCTTAG:
id varchar(36) (primary key)
ProductID varchar(36)
TagID varchar(36)
I find quite a few answers here on Stackoverflow talking about returning full and partial matches. However I am looking for a query which only gives full matches.
Example:
Product A has tags 1, 2, 3
Product B has tags 1, 2
Product C has tags 1, 2, 3
Product D has tags 1, 2, 3, 4
If I query for product A, only product C should be found - as it is the only one having exactly the same tags.
Is this even possible?
Yes, yes, try this way:
with aa as (
select count(*) count
from [PRODUCTTAG]
where ProductID = '19A947C0-6A0F-4A6F-9675-48FBE30A877D'
), bb as
(
select ProductID, count(*) count
from [PRODUCTTAG]
group by ProductID
)
select distinct b.ProductID
from [dbo].[PRODUCTTAG] a join
[dbo].[PRODUCTTAG] b on a.TagID = b.TagID cross join
aa join
bb on aa.count = bb.count and b.ProductID = bb.ProductID
where a.ProductID = '19A947C0-6A0F-4A6F-9675-48FBE30A877D'
declare #PRODUCTTAG table(id int identity(1,1),ProductID int,TagID int)
insert into #PRODUCTTAG VALUES
(1,1),(1,2),(1,3)
,(2,1),(2,2)
,(3,1),(3,2),(3,3)
,(4,1),(4,2),(4,3),(4,4)
;With CTE as
(
select ProductID,count(*)smallCount
FROM #PRODUCTTAG
group by ProductID
)
,CTE1 as
(
select smallCount, count(smallCount)BigCount
from cte
group by smallCount
)
,CTE2 as
(
select * from cTE c
where exists(
select smallCount from cte1 c1
where BigCount>1 and c1.smallCount=c.smallCount
)
)
select * from cte2
--depending upon the output expected join this with #PRODUCTTAG,#Product,#Tag
--like this
--select * from #PRODUCTTAG PT
--where exists(
--select * from cte2 c2 where pt.productid=c2.productid
--)
Or Tell what is final output look like ?
This is a case where I find it simpler to combine all the tags into a single string and compare the strings. But, that is painful in SQL Server until 2016.
So, there is a set based solution:
with pt as (
select pt.*, count(*) over (partition by productid) as cnt
from producttag pt
)
select pt.productid
from pt join
pt pt2
on pt.cnt = pt2.cnt and
pt.productid <> pt2.productid and
pt.tagid = pt2.tagid
where pt2.productid = #x
group by pt.productid, pt.cnt
having count(*) = pt.cnt;
This matches every product to your given product based on the tags. The having clause then ensures that the number of matching tags is the same for the two products. Because the join only considers matching tags, all the tags are the same.

Calculate balance sheet with fastest algorithm

I am implementing accounting software.
In calculating the balance sheet of the hierarchical self-referenced topics, please let me know the fastest algorithm
These are my tables:
Topics table:
TopicID nvarchar(50) -- is Parent Field
ParentID nvarchar(50) -- is Child Field
Description nvarchar(512)
------------DocumentDetal table
DocumentNumber nvarchar(50)
TopicFK nvarchar(50)
Debit decimal(18,0)
Credit decimal(18,0)
Two tables are related with TopicID and TopicFK columns, please let me know how I can calculate balance sheet using a SQL stored procedure.
Followin are data samples:
Following are Documents:
Actually I want following calculation results:
For your SQL Server 2008 R2, Here is for sumDebit and sumCredit. Don't understand how to calculate Res Debit and Res credit but I think you could edit to get your Res value too.
Anyway, this is using CTE thank to Mikael Eriksson in Recursive sum in tree structure
with T as
(
select t.TopicID, t.ParentID, sum(d.Debit) as sumDebit, sum(d.Credit) as sumCredit
from Topics t
left join DocumentDetail d
on t.TopicID = d.TopicFK
group by t.TopicID, t.ParentID
)
,C as
(
select T.TopicID,
T.sumDebit,
T.sumCredit,
T.TopicID as RootID
from T
union all
select T.TopicID,
T.sumDebit,
T.sumCredit,
C.RootID
from T
inner join C
on T.ParentId = C.TopicID
)
select T.TopicID,
T.ParentId,
S.sumDebitIncludingChildren sumDebit,
S.sumCreditIncludingChildren sumCredit
from T
inner join (
select RootID,
sum(sumDebit) as sumDebitIncludingChildren,
sum(sumCredit) as sumCreditIncludingChildren
from C
group by RootID
) as S
on T.TopicID = S.RootID
order by T.TopicID
option (maxrecursion 0);
Tested OK in SQL Fiddle

How to do conditional update on columns using CTE?

I have a table CUST with following layout. There are no constraints. I do see that one ChildID has more than one ParentID associated with it. (Please see the records for ChildID = 115)
Here is what I need -
Wherever one child has more than 1 parent, I want to update those ParentID and ParentName with the ParentID and ParentName which has max match_per. So in the below image, I want ParentID 1111 and ParentName LEE YOUNG WOOK to update all records where ChildId = 115 (since the match_per 0.96 is maximum within the given set). In case there are two parents with equal max match_per, then I want to pick any 1 one of them.
I know it is possible using CTE but I don't know how to update CTE. Can anybody help?
One way of doing it
WITH CTE1 AS
(
SELECT *,
CASE WHEN match_per =
MAX(match_per) OVER (PARTITION BY ChildId)
THEN CAST(ParentId AS CHAR(10)) + ParentName
END AS parentDetailsForMax
FROM CUST
), CTE2 AS
(
SELECT *,
MAX(parentDetailsForMax) OVER (PARTITION BY ChildId) AS maxParentDetailsForMax
FROM CTE1
)
UPDATE CTE2
SET ParentId = CAST(LEFT(maxParentDetailsForMax,10) AS int),
ParentName = SUBSTRING(maxParentDetailsForMax,10,8000)
Getting both the parent id and parent name is a bit tricky. I think the logic is easiest using cross apply:
with toupdate as (
select t.*, p.parentId as new_parentId, p.parentName as new_parentName
max(match_per) over (partition by childid) as max_match_per,
count(*) over (partition by childid) as numparents
from table t cross apply
(select top 1 p.*
from table p
where p.childid = t.childid
order by match_per desc
) p
)
update toupdate
set parentId = new_ParentId,
parentName = new_ParentName
where numparents > 1;
As a note: the fact that parent id and parent name are both stored in the table, potentially multiple times seems like a problem. I would expect to look up the name, given the id, to reduce data redundancy.
Try something like this?? The first CTE will get Max(match_per) for each ChildID. Then, the second will use the new MaxMatchPer to find what its corresponding ParentID should be.
; WITH CTE AS (
SELECT ChildID,MAX(match_per) AS MaxMatchPer
FROM tbl
GROUP BY ChildID
), CTE1 AS (
SELECT t.ParentID, c.ChildID
FROM tbl t
JOIN CTE c
ON c.ChildID = t.ChildID
AND c.MaxMatchPer = t.match_per
)
UPDATE t
SET ParentID = c.ParentID
FROM tbl t
LEFT JOIN CTE1 c
ON c.ChildID = t.ChildID
Also, this is poor normalization. You should not have ParentName nor ChildName in this table.

How to get all child of a given id in SQL Server query

I have two tables in SQL Server database:
category(
itemid,
parentid
)
ArticleAssignedCategories(
categid,
artid
)
categid is a foreign key of itemid
I want to get count of artids and child of that for given itemid (child means categories with parentid of given itemid.)
For example; If given itemid = 1 and in table category have (3,1),(4,1)(5,3)
All of 3, 4, 5 are child of 1
Can anyone help me to write a good query?
Recursive queries can be done using CTE
with CTE(itemid, parentid)
as (
-- start with some category
select itemid, parentid
from category where itemid = <some_itemid>
union all
-- recursively add children
select c.itemid, c.parentid
from category c
join CTE on c.parentid = CTE.itemid
)
select count(*)
from ArticleAssignedCategories a
join CTE on CTE.itemid = a.categid
Here is the query. I hope this may help you
select b.artid,count(b.artid) from category a
inner join ArticleAssignedCategories b on a.itemid = b.artid
group by b.artid

How do you get the last record generated in a recursive CTE?

In the code below I am using a recursive CTE(Common Table Expression) in SQL Server 2005 to try and find the top level parent of a basic hierarchical structure. The rule of this hierarchy is that every CustID has a ParentID and if the CustID has no parent then the ParentID = CustID and it is the highest level.
DECLARE #LookupID int
--Our test value
SET #LookupID = 1
WITH cteLevelOne (ParentID, CustID) AS
(
SELECT a.ParentID, a.CustID
FROM tblCustomer AS a
WHERE a.CustID = #LookupID
UNION ALL
SELECT a.ParentID, a.CustID
FROM tblCustomer AS a
INNER JOIN cteLevelOne AS c ON a.CustID = c.ParentID
WHERE c.CustID <> a.CustomerID
)
So if tblCustomer looks like this:
ParentID CustID
5 5
1 8
5 4
4 1
The result I get from the code above is:
ParentID CustID
4 1
5 4
5 5
What I want is just the last row of that result:
ParentID CustID
5 5
How do I just return the last record generated in the CTE (which would be highest level CustID)?
Also note that there are multiple unrelated CustID hierarchies in this table so I can't just do a SELECT * FROM tblCustomer WHERE ParentID = CustID. I can't order by ParentID or CustID because the ID number is not related to where it is in the hierarchy.
If you just want want the highest recursion depth couldn't you do something like this?Then, when you actually query the CTE just look for the row with max(Depth)? Like so:
DECLARE #LookupID int
--Our test value
SET #LookupID = 1;
WITH cteLevelOne (ParentID, CustID, Depth) AS
(
SELECT a.ParentID, a.CustID, 1
FROM tblCustomer AS a
WHERE a.CustID = #LookupID
UNION ALL
SELECT a.ParentID, a.CustID, c.Depth + 1
FROM tblCustomer AS a
INNER JOIN cteLevelOne AS c ON a.CustID = c.ParentID
WHERE c.CustID <> a.CustID
)
select * from CTELevelone where Depth = (select max(Depth) from CTELevelone)
or, adapting what trevor suggests, this could be used with the same CTE:
select top 1 * from CTELevelone order by Depth desc
I don't think CustomerID was necessarily what you wanted to order by in the case you described, but I wasn't perfectly clear on the question either.
I'm not certain I fully understand the problem, but just to hack & slash at it you could try:
SELECT TOP 1 FROM cteLevelOne ORDER BY CustID DESC
That assumes that the CustID is also in order as in the example, and not something like a GUID.
First the cte will not be finished if any of the parent child are same. As it is a recursive CTE it has to be terminated. Having Parent and cust id same , the loop will not end.
Msg 530, Level 16, State 1, Line 15
The statement terminated. The maximum recursion 100 has been exhausted before statement completion.