Question

我正在尝试将此表达式从SQL转换为LINQ，但对我来说有点太难了，也许你可以帮我解决这个问题！

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

如果你向我们展示你已经尝试过的东西会更容易帮助你，但像这样的Linq表达式会给你相同的结果集

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);

使用子查询的复杂SQL到LINQ转换

1 个答案: