Imbrication des expressions FOR FOR XML

Question

J'ai essayé une requête FOR XML similaire à here sous le sous-titre 'Imbrication de FOR XML Expressions'. Mon problème est que je dois avoir trois niveaux d'éléments XML. Les résultats devraient être quelque chose comme ça.

<StepTree Name="ALFKI"> 
    <Step Name="Foo"> 
    <Result id="123" /> 
    <Result id="456" /> 
    </Step> 
    <Step Name="Bar"> 
    <Result id="789" /> 
    <Result id="987" /> 
    </Step> 
</StepTree > 

J'ai essayé ce type de requête.

SELECT 1 as TAG, 
     NULL as Parent, 
     StepTrees.Name AS [StepTree!1!Name], 
     NULL as [Step!2!Name], 
     NULL as [Result!3!id] 
FROM StepTrees 
WHERE StepTrees.Name = 'ALFKI' 
UNION ALL 
SELECT 2, 
     1, 
     StepTrees.Name, 
     Steps.Name, 
     NULL 
FROM Steps 
JOIN StepTrees ON Steps.StepTreeId = StepTrees.Id 
WHERE StepTrees.Name = 'ALFKI' 
UNION ALL 
SELECT DISTINCT 3, 
     2, 
     StepTrees.Name, 
     Steps.Name, 
     Results.id 
FROM StepTrees 
JOIN Steps ON Steps.StepTreeId = StepTrees.Id 
JOIN Results ON Steps.StepId = Results.StepId 
FOR XML EXPLICIT 

Le code XML résultant est le suivant.

<StepTree Name="ALFKI"> 
    <Step Name="Foo" /> 
    <Step Name="Bar"> 
    <Result id="123" /> 
    <Result id="456" /> 
    <Result id="789" /> 
    <Result id="987" /> 
    </Step> 
</StepTree > 

Toutes les idées?

Answer 1

Utilisez cette requête:

SELECT 1 as TAG, 
    NULL as Parent, 
    StepTrees.Name AS [StepTree!1!Name], 
    NULL as [Step!2!Name], 
    NULL as [Result!3!id] 
FROM StepTrees 
WHERE StepTrees.Name = 'ALFKI' 
UNION ALL 
SELECT 2, 
     1, 
     Null, 
     Steps.Name, 
     NULL 
FROM Steps 
JOIN StepTrees ON Steps.StepTreeId = StepTrees.Id 
WHERE StepTrees.Name = 'ALFKI' 
UNION ALL 
SELECT DISTINCT 3, 
     2, 
     Null, 
     Steps.Name, 
     Results.id 
FROM StepTrees 
JOIN Steps ON Steps.StepTreeId = StepTrees.Id 
JOIN Results ON Steps.StepId = Results.StepId 
ORDER BY [Step!2!Name],[Result!3!id] 
FOR XML EXPLICIT