Nettet19. jan. 2024 · Solution 1 C# ListOfFruits.FirstOrDefault (x => x.Name == "Apple" ).ID You could also load the FirstOrDefault into an object and check for null before trying to access the id. As suggested, in order to avoid a NullRef exception you can do a couple of things: If you are using a version of VS with the Roslyn compiler: C# Nettet14. feb. 2024 · LINQ Distinct by Field If you want to achieve the distinct values for a specific field in the list, you can use the following two methods: 1. Using GroupBy and Select functions In this approach, you need to use two LINQ functions i.e., GroupBy and Select to get the list of unique field values.
LINQ Group By Multiple Columns - Sensible Dev
NettetI have to select specific column from my DataTable using linq I am using this code. ds.Table[0].AsEnumerable().Where(r=>r.Field("productID")==23).CopyToDataTable(); … Nettet16. jan. 2024 · yes, you are totally right. to avoid losing distinct data - those columns need to be included in the group by. Correct? ppr (Peter) January 13, 2024, 7:25pm 6 we can do: using remove duplicate row activity YourDataTableVar.DefaultView.ToTable (True, {ColNameFirst,ColNameLast}) LINQ Also have a look here: community pharmacy impetigo
LINQ to SQL: Multiple joins ON multiple Columns. Is this possible?
NettetHere’s the SQL we want to duplicate in LINQ: SELECT Author, Category, COUNT (ID) As RecipeCount FROM Recipes GROUP BY Author, Category This will create the following output: [table id=4 /] In order to group by multiple columns, the structure of our queries is basically the same as before. Nettet23. mar. 2016 · Using the two LINQ methods, this can be implemented as follows. var result = first .Zip (second, (f, s) => new Type [] {a, b}) .SelectMany (x => x); As you can see, we first use Zip to take one element from each of the lists, and combine them into a small array of two elements, and then flatten all those arrays using SelectMany. NettetSelect query in LINQ Select method is used to select one or more items from collection or list object, here we see some example of linq select statement . variableName.Select (s => s.Name); There are various ways we can select some records or single record from a collection object. community pharmacy hypertension scheme