Verwenden eines CTE zum Auflisten der Eltern als Spalten

Question

Ich habe zwei Tabellen, ticket und problem. Jedes Ticket hat ein Problem und jedes Problem kann ein Elternproblem haben oder nicht. Beispieldaten:

create table #problem (problem_type_id int, problem_type_name varchar(32), parent_id int) 
insert #problem 
select 1, 'Change Request', NULL union 
select 5, 'Level 1', 1 union 
select 10, 'Software', 5 union 
select 15, 'Applications', 10 union 
select 20, 'Update', 15 union 
select 6, 'Level 2', 1 union 
select 11, 'Hardware', 6 union 
select 16, 'Install', 11 

create table #ticket (ticket_id int, problem_type_id int) 
insert #ticket 
select 1, 20 union 
select 2, 16 

Hier ist das Ergebnis, das ich brauche:

+-----------+-----------------+-----------------+-----------------+-----------------+-----------------+ 
| ticket_id | problem_level_1 | problem_level_2 | problem_level_3 | problem_level_4 | problem_level_5 | 
+-----------+-----------------+-----------------+-----------------+-----------------+-----------------+ 
| 1   | Change Request | Level 1   | Software  | Applications | Update   | 
| 2   | Change Request | Level 2   | Hardware  | Install   |     | 
+-----------+-----------------+-----------------+-----------------+-----------------+-----------------+ 

Unter der Annahme, dass es höchstens vier Nachkommen von einem Top-Level-Eltern sein wird, wie kann ich die Probleme in der umgekehrten Reihenfolge erhalten mit der oberste Elternteil zuerst? Hier ist, was ich bisher:

;with probs (parent_id, problem_type_id, problem_type_name, level) 
as 
(
    -- anchor member definition 
    select parent_id, problem_type_id, problem_type_name, 0 as level 
    from #problem 
    where parent_id is null 
    union all 
    -- recursive member definition 
    select a.parent_id, a.problem_type_id, a.problem_type_name, level + 1 
    from #problem a 
    join probs as b on b.problem_type_id = a.parent_id 
) 
select t.ticket_id, 
p1.level, /* p1.problem_type_id, */ p1.problem_type_name, 
p2.level, /* p2.problem_type_id, */ p2.problem_type_name, 
p3.level, /* p3.problem_type_id, */ p3.problem_type_name, 
p4.level, /* p4.problem_type_id, */ p4.problem_type_name, 
p5.level, /* p5.problem_type_id, */ p5.problem_type_name 
from #ticket t 
join probs p1 on p1.problem_type_id = t.problem_type_id 
left join probs p2 on p2.problem_type_id = p1.parent_id and p2.level = p1.level - 1 
left join probs p3 on p3.problem_type_id = p2.parent_id and p3.level = p2.level - 1 
left join probs p4 on p4.problem_type_id = p3.parent_id and p4.level = p3.level - 1 
left join probs p5 on p5.problem_type_id = p4.parent_id and p5.level = p4.level - 1 
order by t.ticket_id 

Ich kann nicht scheinen, um herauszufinden, wie die Ebene 0 Spalten zuerst erhalten, dann die Kinder.

Answer 1

Sie sind fast da. Sie können diese mit PIVOT wie so erreichen:

SAMPLE DATA:

CREATE TABLE #problem(problem_type_id INT 
       , problem_type_name VARCHAR(32) 
       , parent_id   INT); 

INSERT INTO #problem 
     SELECT 1 
      , 'Change Request' 
      , NULL 
     UNION 
     SELECT 5 
      , 'Level 1' 
      , 1 
     UNION 
     SELECT 10 
      , 'Software' 
      , 5 
     UNION 
     SELECT 15 
      , 'Applications' 
      , 10 
     UNION 
     SELECT 20 
      , 'Update' 
      , 15 
     UNION 
     SELECT 6 
      , 'Level 2' 
      , 1 
     UNION 
     SELECT 11 
      , 'Hardware' 
      , 6 
     UNION 
     SELECT 16 
      , 'Install' 
      , 11; 

CREATE TABLE #ticket(ticket_id  INT 
       , problem_type_id INT); 

INSERT INTO #ticket 
     SELECT 1 
      , 20 
     UNION 
     SELECT 2 
      , 16; 

QUERY:

;WITH probs(parent_id 
     , problem_type_id 
     , problem_type_name 
     , level) 
    AS (
    -- anchor member definition 
    SELECT parent_id 
     , problem_type_id 
     , problem_type_name 
     , 0 AS level 
    FROM  #problem 
    WHERE parent_id IS NULL 
    UNION ALL 
    -- recursive member definition 
    SELECT a.parent_id 
     , a.problem_type_id 
     , a.problem_type_name 
     , level + 1 
    FROM #problem a 
      JOIN probs AS b ON b.problem_type_id = a.parent_id) 
    SELECT t.ticket_id 
     , p1.level 

      /* p1.problem_type_id, */ 

     , p1.problem_type_name 
    INTO #preResult 
    FROM  #ticket t 
      JOIN probs p1 ON p1.problem_type_id = t.problem_type_id 
      LEFT JOIN probs p2 ON p2.problem_type_id = p1.parent_id 
          AND p2.level = p1.level - 1 
      LEFT JOIN probs p3 ON p3.problem_type_id = p2.parent_id 
          AND p3.level = p2.level - 1 
      LEFT JOIN probs p4 ON p4.problem_type_id = p3.parent_id 
          AND p4.level = p3.level - 1 
      LEFT JOIN probs p5 ON p5.problem_type_id = p4.parent_id 
          AND p5.level = p4.level - 1 
    UNION 
    SELECT t.ticket_id 
     , p2.level 

      /* p2.problem_type_id, */ 

     , p2.problem_type_name 
    FROM  #ticket t 
      JOIN probs p1 ON p1.problem_type_id = t.problem_type_id 
      LEFT JOIN probs p2 ON p2.problem_type_id = p1.parent_id 
          AND p2.level = p1.level - 1 
      LEFT JOIN probs p3 ON p3.problem_type_id = p2.parent_id 
          AND p3.level = p2.level - 1 
      LEFT JOIN probs p4 ON p4.problem_type_id = p3.parent_id 
          AND p4.level = p3.level - 1 
      LEFT JOIN probs p5 ON p5.problem_type_id = p4.parent_id 
          AND p5.level = p4.level - 1 
    UNION 
    SELECT t.ticket_id 
     , p3.level 

      /* p3.problem_type_id, */ 

     , p3.problem_type_name 
    FROM  #ticket t 
      JOIN probs p1 ON p1.problem_type_id = t.problem_type_id 
      LEFT JOIN probs p2 ON p2.problem_type_id = p1.parent_id 
          AND p2.level = p1.level - 1 
      LEFT JOIN probs p3 ON p3.problem_type_id = p2.parent_id 
          AND p3.level = p2.level - 1 
      LEFT JOIN probs p4 ON p4.problem_type_id = p3.parent_id 
          AND p4.level = p3.level - 1 
      LEFT JOIN probs p5 ON p5.problem_type_id = p4.parent_id 
          AND p5.level = p4.level - 1 
    UNION 
    SELECT t.ticket_id 
     , p4.level 

      /* p4.problem_type_id, */ 

     , p4.problem_type_name 
    FROM  #ticket t 
      JOIN probs p1 ON p1.problem_type_id = t.problem_type_id 
      LEFT JOIN probs p2 ON p2.problem_type_id = p1.parent_id 
          AND p2.level = p1.level - 1 
      LEFT JOIN probs p3 ON p3.problem_type_id = p2.parent_id 
          AND p3.level = p2.level - 1 
      LEFT JOIN probs p4 ON p4.problem_type_id = p3.parent_id 
          AND p4.level = p3.level - 1 
      LEFT JOIN probs p5 ON p5.problem_type_id = p4.parent_id 
          AND p5.level = p4.level - 1 
    UNION 
    SELECT t.ticket_id 
     , p5.level 

      /* p5.problem_type_id, */ 

     , p5.problem_type_name 
    FROM #ticket t 
      JOIN probs p1 ON p1.problem_type_id = t.problem_type_id 
      LEFT JOIN probs p2 ON p2.problem_type_id = p1.parent_id 
          AND p2.level = p1.level - 1 
      LEFT JOIN probs p3 ON p3.problem_type_id = p2.parent_id 
          AND p3.level = p2.level - 1 
      LEFT JOIN probs p4 ON p4.problem_type_id = p3.parent_id 
          AND p4.level = p3.level - 1 
      LEFT JOIN probs p5 ON p5.problem_type_id = p4.parent_id 
          AND p5.level = p4.level - 1; 

SELECT ticket_id, problem_level_1=[0] 
      , problem_level_2=[1] 
      , problem_level_3=[2] 
      , problem_level_4=[3] 
      , problem_level_5=[4] 
FROM 
     (SELECT ticket_id 
      , level 
      , problem_type_name 
     FROM #preResult) AS p PIVOT(MAX(problem_type_name) FOR [level] IN([0] 
                  , [1] 
                  , [2] 
                  , [3] 
                  , [4])) AS unpvt; 

ERGEBNIS: