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Counting all childs and sub-childs of a node in tree

  • September 4, 2009 at 12:17 am

    #103816

    Hi friends,

    I have one problem.

    I have one tree which I have saved in sql server table like

    ID Node ParentID

    1 A 0

    2 B 1

    3 C 1

    4 D 2

    5 E 2

    6 F 3

    7 G 3

    8 H 3

    9 I 4

    10 J 4

    11 K 10

    12 L 11

    ParentID stores ID of the parent of the node.

    Now suppose I have only one node given from the table, say "A", I have to count all its child nodes up to the leafs. In above table under node "A", there are in-total 11 child and sub-child nodes , if I have node "B" then there are total 6 child and sub-child nodes under it.

    How to achieve this in sql server (withought using loops) if we are provided with only one node from the tree and we have to count all the child and sub-child up to leafs? Please remember tree may have N number of nodes, I have just used 12 here. We don't know total number nodes in the tree.

    [Sorry for the language-related mistakes].

  • September 4, 2009 at 1:21 am

    #1049234

    Recursive CTE's are the way to go....

    Try this link http://www.sqlservercentral.com/articles/Development/recursivequeriesinsqlserver2005/1760/


    Clear Sky SQL
    My Blog[/url]

  • September 4, 2009 at 1:52 am

    #1049243

    thanks for replying dave.....

    Actually I have used recursive queries with some different scenarios in hierarchies. But here the case is little different i have to count all nodes, for this i will have traverse from top to bottom.

    In case of the example i have given in my question,

    from A i will have to search child nodes, which are B and C.

    then from B i will have to get D and E and from C have to find F, G and H. then again i will have to look for the child nodes of these nodes also.

    I tried the recursive query, but I didn't find any fruitful result.

    But ok, I will try it again. Thanks once again for reply.

  • September 4, 2009 at 2:13 am

    #1049249

    Try this, possibly not the most efficient, i suspect that a hierarchyId-esque based query may be faster over a large dataset , but should do

    Create table #RecursTest

    (

    ID integer,

    Node varchar(10),

    ParentId integer

    )

    insert into #RecursTest(Id,Node,ParentID) values(1, 'A', 0)

    insert into #RecursTest(Id,Node,ParentID) values(2, 'B', 1)

    insert into #RecursTest(Id,Node,ParentID) values(3, 'C', 1)

    insert into #RecursTest(Id,Node,ParentID) values(4, 'D', 2)

    insert into #RecursTest(Id,Node,ParentID) values(5, 'E', 2)

    insert into #RecursTest(Id,Node,ParentID) values(6, 'F', 3)

    insert into #RecursTest(Id,Node,ParentID) values(7, 'G', 3)

    insert into #RecursTest(Id,Node,ParentID) values(8, 'H', 3)

    insert into #RecursTest(Id,Node,ParentID) values(9, 'I', 4)

    insert into #RecursTest(Id,Node,ParentID) values(10, 'J', 4)

    insert into #RecursTest(Id,Node,ParentID) values(11, 'K', 10)

    insert into #RecursTest(Id,Node,ParentID) values(12, 'L', 11)

    go

    with cteRecurs(AncestorId,Id,Node,ParentId)

    as

    (

    Select Id,Id,Node,ParentId

    from #RecursTest

    union all

    Select cteRecurs.AncestorId,#RecursTest.Id,#RecursTest.Node,#RecursTest.ParentId

    from cteRecurs,

    #RecursTest

    where #RecursTest.ParentId = cteRecurs.Id

    )

    select AncestorId,count(*)-1 From cteRecurs

    group by AncestorId


    Clear Sky SQL
    My Blog[/url]

  • September 8, 2009 at 2:04 am

    #1050338

    hey dave, sorry for replying late.

    i tested it with the same logic but in a different way. it worked. also i tried it using cursors too. that also worked. but as cursors are not that efficient, i kept this CTE logic.

    thanks for the help.:-)

  • February 12, 2013 at 10:02 am

    #1587096

    Hi All,

    I need an urgent help to build some logic in Oracle DB.

    I have a table called TREE and in that we have data based on hierarchies.

    We have columns like DataID and ParentID and DataID column is unique one.

    And the data for DataID and ParentID will be this is like parent and child relation ship.

    I need to get the count of all DataID's and Sub-dataID's of ParentID.

    I need to get the count of this without using Start With connect by option.

    Is there a way to get this done...

    Thanks

    Anilkumar B

  • May 19, 2014 at 6:22 am

    #1714589

    Thank u for the post. It helps me lot.

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