Dans mon projet, j'utilise EntityFramework 4 pour travailler avec des données. J'ai trouvé d'horribles problèmes de performance avec une requête simple. Quand j'ai regardé le profileur sur une requête sql, généré par EF4, j'ai été choqué.Requêtes Linq dans Entity Framework 4. Performances horribles
J'ai quelques tables dans mon modèle de données d'entité:
Il semble assez simple. J'essaie de sélectionner tous les éléments du produit de la catégorie spécifiée avec toutes les propriétés de navigation connexes.
J'ai écrit cette requête LINQ:
ObjectSet<ProductItem> objectSet = ...;
int categoryId = ...;
var res = from pi in objectSet.Include("Product").Include("Inventory").Include("Inventory.Storage")
where pi.Product.CategoryId == categoryId
select pi;
EF a généré cette requête SQL:
SELECT [Project1].[pintId1] AS [pintId],
[Project1].[pintId] AS [pintId1],
[Project1].[intProductId] AS [intProductId],
[Project1].[nvcSupplier] AS [nvcSupplier],
[Project1].[ nvcArticle] AS [ nvcArticle],
[Project1].[nvcBarcode] AS [nvcBarcode],
[Project1].[bIsActive] AS [bIsActive],
[Project1].[dtDeleted] AS [dtDeleted],
[Project1].[pintId2] AS [pintId2],
[Project1].[nvcName] AS [nvcName],
[Project1].[intCategoryId] AS [intCategoryId],
[Project1].[ncProductType] AS [ncProductType],
[Project1].[C1] AS [C1],
[Project1].[pintId3] AS [pintId3],
[Project1].[intProductItemId] AS [intProductItemId],
[Project1].[intStorageId] AS [intStorageId],
[Project1].[dAmount] AS [dAmount],
[Project1].[mPrice] AS [mPrice],
[Project1].[dtModified] AS [dtModified],
[Project1].[pintId4] AS [pintId4],
[Project1].[nvcName1] AS [nvcName1],
[Project1].[bIsDefault] AS [bIsDefault]
FROM (SELECT [Extent1].[pintId] AS [pintId],
[Extent1].[intProductId] AS [intProductId],
[Extent1].[nvcSupplier] AS [nvcSupplier],
[Extent1].[ nvcArticle] AS [ nvcArticle],
[Extent1].[nvcBarcode] AS [nvcBarcode],
[Extent1].[bIsActive] AS [bIsActive],
[Extent1].[dtDeleted] AS [dtDeleted],
[Extent2].[pintId] AS [pintId1],
[Extent3].[pintId] AS [pintId2],
[Extent3].[nvcName] AS [nvcName],
[Extent3].[intCategoryId] AS [intCategoryId],
[Extent3].[ncProductType] AS [ncProductType],
[Join3].[pintId1] AS [pintId3],
[Join3].[intProductItemId] AS [intProductItemId],
[Join3].[intStorageId] AS [intStorageId],
[Join3].[dAmount] AS [dAmount],
[Join3].[mPrice] AS [mPrice],
[Join3].[dtModified] AS [dtModified],
[Join3].[pintId2] AS [pintId4],
[Join3].[nvcName] AS [nvcName1],
[Join3].[bIsDefault] AS [bIsDefault],
CASE
WHEN ([Join3].[pintId1] IS NULL) THEN CAST(NULL AS int)
ELSE 1
END AS [C1]
FROM [ProductItem] AS [Extent1]
INNER JOIN [Product] AS [Extent2]
ON [Extent1].[intProductId] = [Extent2].[pintId]
LEFT OUTER JOIN [Product] AS [Extent3]
ON [Extent1].[intProductId] = [Extent3].[pintId]
LEFT OUTER JOIN (SELECT [Extent4].[pintId] AS [pintId1],
[Extent4].[intProductItemId] AS [intProductItemId],
[Extent4].[intStorageId] AS [intStorageId],
[Extent4].[dAmount] AS [dAmount],
[Extent4].[mPrice] AS [mPrice],
[Extent4].[dtModified] AS [dtModified],
[Extent5].[pintId] AS [pintId2],
[Extent5].[nvcName] AS [nvcName],
[Extent5].[bIsDefault] AS [bIsDefault]
FROM [Inventory] AS [Extent4]
INNER JOIN [Storage] AS [Extent5]
ON [Extent4].[intStorageId] = [Extent5].[pintId]) AS [Join3]
ON [Extent1].[pintId] = [Join3].[intProductItemId]
WHERE [Extent2].[intCategoryId] = 8 /* @p__linq__0 */) AS [Project1]
ORDER BY [Project1].[pintId1] ASC,
[Project1].[pintId] ASC,
[Project1].[pintId2] ASC,
[Project1].[C1] ASC
Pour 7000 enregistrements dans la base de données et ~ 1000 enregistrement dans la catégorie spécifiée id temps d'exécution de cette requête environ 10 secondes . Rien d'étonnant si regardez ceci:
FROM [ProductItem] AS [Extent1]
INNER JOIN [Product] AS [Extent2]
ON [Extent1].[intProductId] = [Extent2].[pintId]
LEFT OUTER JOIN [Product] AS [Extent3]
ON [Extent1].[intProductId] = [Extent3].[pintId]
***LEFT OUTER JOIN (SELECT ....***
Nested sélectionner dans ... Horrible ... rejoindre J'ai essayé de changer la requête LINQ, mais je reçois même requête SQL émis.
Une solution utilisant des procédures stockées n'est pas acceptable pour moi, car j'utilise la base de données SQL Compact.
Votre anglais n'est pas si mal :) Question bien formée aussi. +1 – Aren
Vous pouvez utiliser http://imgur.com/ pour partager des images. – Steven
Qu'est-ce qui est inclus? Pourquoi pas juste _from pi dans objectSet où pi.Product.CategoryId == categoryId select pi_? –