How to drill down in recursive cte?

  • I have the following working example:

    DROP TABLE IF EXISTS consignment_levels;
    GO

    CREATE TABLE consignment_levels(
    consignment_id INT NOT NULL,
    parent_id CHAR(10) NULL,
    level_id CHAR(10) NOT NULL,
    level_type CHAR(10) NOT NULL,--case, master_case, pallet
    );

    CREATE UNIQUE INDEX consignment_levels_U01 ON consignment_levels (consignment_id,parent_id,level_id);
    GO


    DECLARE @v_consignment_id INT = 1000;

    DECLARE @c_pallet CHAR(6) = 'PALLET',
    @c_master_case CHAR(6) = 'MASTER',
    @c_case CHAR(4) = 'CASE',
    @c_box CHAR(3) = 'BOX';


    INSERT INTO consignment_levels(consignment_id,parent_id,level_id, level_type)

    VALUES (@v_consignment_id,NULL,'P1',@c_pallet),
    (@v_consignment_id,NULL,'P2',@c_pallet),
    (@v_consignment_id,NULL,'P3',@c_pallet),
    (@v_consignment_id,NULL,'P4',@c_pallet),
    (@v_consignment_id,NULL,'P5',@c_pallet),
    (@v_consignment_id,NULL,'P6',@c_pallet),
    (@v_consignment_id,'P2','M1',@c_master_case),
    (@v_consignment_id,'P2','M2',@c_master_case),
    (@v_consignment_id,'P2','M3',@c_master_case),
    (@v_consignment_id,'P2','M4',@c_master_case),
    (@v_consignment_id,'P3','M11',@c_master_case),
    (@v_consignment_id,'P3','M12',@c_master_case),
    (@v_consignment_id,'P3','M13',@c_master_case),
    (@v_consignment_id,'P3','M14',@c_master_case),
    (@v_consignment_id,'M3','C1',@c_case),
    (@v_consignment_id,'M3','C2',@c_case),
    (@v_consignment_id,'M3','C3',@c_case),
    (@v_consignment_id,'M3','C4',@c_case),
    (@v_consignment_id,'M3','C5',@c_case),
    (@v_consignment_id,'M3','C6',@c_case),
    (@v_consignment_id,'M3','C7',@c_case),
    (@v_consignment_id,'M3','C8',@c_case),
    (@v_consignment_id,'M3','C9',@c_case),
    (@v_consignment_id,'M2','C10',@c_case),
    (@v_consignment_id,'M4','C30',@c_case),
    (@v_consignment_id,'M4','C20',@c_case),
    (@v_consignment_id,'C1','B1',@c_box),
    (@v_consignment_id,'C1','B2',@c_box),
    (@v_consignment_id,'C1','B3',@c_box),
    (@v_consignment_id,'C1','B4',@c_box),
    (2,NULL,'P20',@c_pallet),
    (2,NULL,'P30',@c_pallet),
    (2,NULL,'P40',@c_pallet);

    WITH consignment_tree (consignment_id,parent_id,level_id, level_type,tree_level)
    AS
    (
    SELECT cc.consignment_id,
    cc.parent_id,
    cc.level_id,
    cc.level_type,
    0
    FROM consignment_levels cc
    WHERE cc.parent_id IS NULL

    UNION ALL

    SELECT cc.consignment_id,
    cc.parent_id,
    cc.level_id,
    cc.level_type,
    tree_level+1
    FROM consignment_levels cc
    INNER JOIN consignment_tree ct
    ON ct.level_id = cc.parent_id
    AND ct.consignment_id = cc.consignment_id
    )
    SELECT * FROM consignment_tree ct
    WHERE ct.consignment_id = @v_consignment_id
    ORDER BY ct.tree_level,
    ct.parent_id,
    ct.level_id
    OPTION (MAXRECURSION 5);

    The same type of cte is wrapped in a view and works as expected.

    Now I have a requirement to drill down and to show the structure from a specific record down. Based on my example above, if the user requests to see the structure from Master M3 onwards the system should return the following records:

    1000 M3 C1 CASE

    1000 M3 C2 CASE

    1000 M3 C3 CASE

    1000 M3 C4 CASE

    1000 M3 C5 CASE

    1000 M3 C6 CASE

    1000 M3 C7 CASE

    1000 M3 C8 CASE

    1000 M3 C9 CASE

    1000 C1 B1 BOX

    1000 C1 B2 BOX

    1000 C1 B3 BOX

    1000 C1 B4 BOX

    All the cases, which belong to M3 master and all the boxes which belong to those cases.

    Any suggestion will be extremely appreciated as usual.

     

    Thank you.

    • This topic was modified 2 years, 2 months ago by  BOR15K.
  • Does filtering the first part of the cte return the data you need?

    WHERE level_id = 'M3'

    with

    WHERE tree_level > 0

    If so you could turn it into a table function which will work as a parameterised view.

  • Yes, function is a bit of an issue here - has to be a model in Java at the end, so either view or table.

  • Is the hierarchy limited to those four levels? If so you could always include a Pallet, Master and Case column in the view. Assuming the level_ids don't cross level type,  your query view could use an OR to avoid dynamically choosing a column to filter.

    DROP VIEW IF EXISTS dbo.v_consignment_tree
    GO

    CREATE VIEW dbo.v_consignment_tree AS

    WITH consignment_tree (consignment_id,parent_id,level_id, level_type,tree_level, c_pallet, c_master_case, c_case)
    AS
    (
    SELECT cc.consignment_id,
    cc.parent_id,
    cc.level_id,
    cc.level_type,
    0 ,
    cc.level_id AS c_pallet,
    CONVERT(VARCHAR(10),null) as c_master_case,
    CONVERT(VARCHAR(10),null) as c_case
    FROM consignment_levels cc
    WHERE cc.parent_id IS NULL

    UNION ALL

    SELECT cc.consignment_id,
    cc.parent_id,
    cc.level_id,
    cc.level_type,
    tree_level+1,
    ct.c_pallet,
    iif(cc.level_type = 'MASTER', cc.level_id, ct.c_master_case) as c_master_case,
    iif(cc.leveL_type = 'CASE', cc.level_id, ct.c_case) as c_case
    FROM consignment_levels cc
    INNER JOIN consignment_tree ct
    ON ct.level_id = cc.parent_id
    AND ct.consignment_id = cc.consignment_id
    )
    SELECT * FROM consignment_tree ct

    GO

    DECLARE @Consignment_id INT = 1000,
    @Level_id VARCHAR(10) = 'M3'

    SELECT *
    FROM dbo.v_consignment_tree
    WHERE consignment_id = @Consignment_id
    AND ( c_pallet = @Level_id
    OR c_master_case = @Level_id
    OR c_case = @Level_id
    )

    Adding a hierarchyid might be an option. I had a go at it with your data. I think it works, but I manually created the node column so you'd have to come up with a way to do that. If each item is assigned a number, you could probably use a recursive cte to generate the node strings. Might be more hassle than it's worth though.

    DROP TABLE IF EXISTS consignment_levels;
    GO

    CREATE TABLE consignment_levels
    (
    Consignment_ID INT NOT NULL,
    Consignment_Node hierarchyid NOT NULL,
    Consignment_Code VARCHAR(10) NOT NULL,
    Consignment_Level VARCHAR(10) NOT NULL,

    );


    DECLARE @v_consignment_id INT = 1000;

    DECLARE @c_pallet CHAR(6) = 'PALLET',
    @c_master_case CHAR(6) = 'MASTER',
    @c_case CHAR(4) = 'CASE',
    @c_box CHAR(3) = 'BOX';


    INSERT INTO consignment_levels(Consignment_ID,Consignment_Node,Consignment_Code, Consignment_Level)

    VALUES (@v_consignment_id,'/1/','P1',@c_pallet),
    (@v_consignment_id,'/2/','P2',@c_pallet),
    (@v_consignment_id,'/3/','P3',@c_pallet),
    (@v_consignment_id,'/4/','P4',@c_pallet),
    (@v_consignment_id,'/5/','P5',@c_pallet),
    (@v_consignment_id,'/6/','P6',@c_pallet),
    (@v_consignment_id,'/2/1/','M1',@c_master_case),
    (@v_consignment_id,'/2/2/','M2',@c_master_case),
    (@v_consignment_id,'/2/3/','M3',@c_master_case),
    (@v_consignment_id,'/2/4/','M4',@c_master_case),
    (@v_consignment_id,'/3/5/','M11',@c_master_case),
    (@v_consignment_id,'/3/6/','M12',@c_master_case),
    (@v_consignment_id,'/3/7/','M13',@c_master_case),
    (@v_consignment_id,'/3/8/','M14',@c_master_case),
    (@v_consignment_id,'/2/3/1/','C1',@c_case),
    (@v_consignment_id,'/2/3/2/','C2',@c_case),
    (@v_consignment_id,'/2/3/3/','C3',@c_case),
    (@v_consignment_id,'/2/3/4/','C4',@c_case),
    (@v_consignment_id,'/2/3/5/','C5',@c_case),
    (@v_consignment_id,'/2/3/6/','C6',@c_case),
    (@v_consignment_id,'/2/3/7/','C7',@c_case),
    (@v_consignment_id,'/2/3/8/','C8',@c_case),
    (@v_consignment_id,'/2/3/9/','C9',@c_case),
    (@v_consignment_id,'/2/2/1/','C10',@c_case),
    (@v_consignment_id,'/2/4/1/','C30',@c_case),
    (@v_consignment_id,'/2/4/2/','C20',@c_case),
    (@v_consignment_id,'/2/3/1/1/','B1',@c_box),
    (@v_consignment_id,'/2/3/1/2/','B2',@c_box),
    (@v_consignment_id,'/2/3/1/3/','B3',@c_box),
    (@v_consignment_id,'/2/3/1/4/','B4',@c_box),
    (2,'/20/','P20',@c_pallet),
    (2,'/30/','P30',@c_pallet),
    (2,'/40/','P40',@c_pallet),
    (@v_consignment_id,'/20/15/','M15',@c_master_case),
    (@v_consignment_id,'/30/16/','M16',@c_master_case),
    (@v_consignment_id,'/30/17/','M17',@c_master_case),
    (@v_consignment_id,'/20/15/100/','C100',@c_case),
    (@v_consignment_id,'/20/15/200/','C200',@c_case),
    (@v_consignment_id,'/20/15/201/','C201',@c_case)

    DECLARE @Parent VARCHAR(100) = 'M3', --'P20'
    @ParentNode HIERARCHYID
    SET @ParentNode = (SELECT Consignment_Node FROM consignment_levels WHERE Consignment_Code = @Parent)

    SELECT Consignment_Code,
    Consignment_Level,
    Consignment_Node.ToString() AS NodeText,
    Consignment_Node.GetLevel() AS NodeLevel,
    Consignment_Node
    FROM consignment_levels
    WHERE Consignment_Node.IsDescendantOf(@ParentNode) = 1
  • I was afraid you will be using the nodes.

  • BOR15K wrote:

    I was afraid you will be using the nodes.

    What makes it tricky is you need to show the children of an entity at any level

    Here's a potential alternative. If you concat the levels to create a pseudo-hierarchyid you can use patindex to identify rows there the variable level_id is earlier in the string than the level_id of the row. In the case of M3, P2 is earlier in the string so it is excluded.

    GO
    CREATE OR ALTER VIEW dbo.vconsignment_tree
    AS

    WITH consignment_tree (consignment_id,parent_id,level_id, level_type,tree_level, level_id_string)
    AS
    ( SELECT cc.consignment_id,cc.parent_id,cc.level_id,
    cc.level_type,0 ,
    CONVERT(VARCHAR(100),CONCAT('/', LTRIM(RTRIM(cc.level_id)), '/')) AS level_id_string
    FROM consignment_levels cc
    WHERE cc.parent_id IS NULL
    UNION ALL
    SELECT cc.consignment_id,
    cc.parent_id,cc.level_id,cc.level_type,tree_level+1,
    CONVERT(VARCHAR(100),CONCAT(ct.level_id_string,LTRIM(RTRIM(cc.level_id)), '/')) as level_id_string
    FROM consignment_levels cc
    INNER JOIN consignment_tree ct ON ct.level_id = cc.parent_id
    AND ct.consignment_id = cc.consignment_id )

    SELECT * FROM consignment_tree ct


    GO
    DECLARE @consignment_id int = 1000,
    @level_id varchar(20) = 'M3'
    DECLARE @level_id_string varchar(20) = concat('%', @level_id, '%')

    SELECT *
    FROM dbo.vconsignment_tree AS a
    WHERE consignment_id = @consignment_id
    AND patindex(@level_id_string, level_id_string) > 0
    AND patindex(@level_id_string, level_id_string) <= patindex (concat('%', rtrim(a.level_id), '%') , level_id_string)

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