复杂的SQL LINQ转换与子查询

Question

我想从SQL转换成LINQ这个表达式，但对我来说有点太难了，也许你可以帮助我这个！

SELECT  TOP (2) RecipeID, UserID, Name, Servings, PreparationTime, TotalTime, DifficultyLevelID, CuisineID, DishID, MainIngredientID, PriceLevelID, FlavourID, Instructions, 
         Notes, Thumbnail, VideoLink 
FROM   dbo.Recipes 
WHERE  (RecipeID NOT IN 
          (SELECT DISTINCT Recipes_1.RecipeID 
          FROM   dbo.Allergies INNER JOIN 
                dbo.UsersAllergies ON dbo.Allergies.AllergyID = dbo.UsersAllergies.AllergyID INNER JOIN 
                dbo.IngredientsAllergies ON dbo.Allergies.AllergyID = dbo.IngredientsAllergies.AllergyID INNER JOIN 
                dbo.Ingredients ON dbo.IngredientsAllergies.IngredientID = dbo.Ingredients.IngredientID INNER JOIN 
                dbo.RecipesIngredients ON dbo.Ingredients.IngredientID = dbo.RecipesIngredients.IngredientID INNER JOIN 
                dbo.Recipes AS Recipes_1 ON dbo.RecipesIngredients.RecipeID = Recipes_1.RecipeID INNER JOIN 
                dbo.Users ON dbo.UsersAllergies.UserID = dbo.Users.UserID INNER JOIN 
                dbo.AllergyFactors ON dbo.IngredientsAllergies.AllergyFactorID = dbo.AllergyFactors.AllergyFactorID 
          WHERE  (dbo.Users.UserID = 3) AND (dbo.AllergyFactors.AllergyFactorID < 3))) 

Answer 1

这将是更容易帮助你，如果你向我们展示你已经尝试过，但像这样的LINQ表达式应该给你相同的结果集

var query = (from rec in context.Recipes 
      where !(from al in context.Allergies 
        from ua in context.UsersAllergies.Where(x => al.AllergyID == x.AllergyID) 
        from ia in context.IngredientsAllergies.Where(x => al.AllergyID == x.AllergyID) 
        from in in context.Ingredients.Where(x => ia.IngredientID == x.IngredientID) 
        from ri in context.RecipesIngredients.Where(x => in.IngredientID == x.IngredientID) 
        from re in context.Recipes.Where(x => ri.RecipeID == x.RecipeID) 
        from us in context.Users.Where(x => ua.UserID == x.UserID) 
        from af in context.AllergyFactors.Where(x => ia.AllergyFactorID == x.AllergyFactorID) 
        where us.UserID == 3 && af.AllergyFactorID < 3 
        select re.RecipeID) 
        .Distinct() 
        .Contains(rec.RecipeID) 
      select new 
      { 
       rec.RecipeID, 
       rec.UserID, 
       rec.Name, 
       rec.Servings, 
       rec.PreparationTime, 
       rec.TotalTime, 
       rec.DifficultyLevelID, 
       rec.CuisineID, 
       rec.DishID, 
       rec.MainIngredientID, 
       rec.PriceLevelID, 
       rec.FlavourID, 
       rec.Instructions, 
       rec.Notes, 
       rec.Thumbnail, 
       rec.VideoLink 
      }).Take(2);