Linq - does not contain a definition for 'Contains'

Question

User379720387 posted

I have an array of ServiceGrid items called services, the relevant properties are shown below:

svcId / svcName / svcBillingRate
5 / serviceA / 10.00
19 / serviceB / 19.25
11 / serviceC / 24.00
17 / serviceD / 4.50
2 / serviceE / 9.00

also have a hashset<int> addOnOptions that has a number of svcIds, say 11 and 17

My objective is to end up with:

 5 / serviceA / 10.00 
19 / serviceB / 19.25 
 2 / serviceE / 9.00

var theSelectedAddOns = addOnOptions.ToList().Where(x => new[] {services.ToList()}.Contains(x)); 

This gives the following errors:

'List<ServiceGrid>[]' does not contain a definition for 'Contains' and the best extension method overload 'MemoryExtensions.Contains<int>(ReadOnlySpan<int>, int)' requires a receiver of type 'ReadOnlySpan<int>'

In SQL this would be very easy:

select * from services where svcId in (5, 19, 2)

Looking for ideas on how to proceed.

Answer 1

User303363814 posted

var result = services.Where(svc => !addOnOptions.Any(aoo => aoo == svc..svcId));

Answer 2

User1120430333 posted

Contains() I thought was a string function. So to me,  everything in the array must be converted to string,  and  'x' itself must be x.ToString(). You might have to use a substring() based on the length of the search criteria's length in order to get the hit. 

Even the link  is talking about a string comparison type.

MemoryExtensions.Contains Method (System) | Microsoft Docs

C# | Check if an array contain the elements that match the specified conditions - GeeksforGeeks

I think you need another approach, becuase Linq is not a  panacea solution.

Answer 3

User379720387 posted

It is a beauty!

var result = services.Where(svc => addOnOptions.Any(aoo => aoo == svc..svcId));

Without the negation.

Thnx

@DA924 .... no kidding, I am torn between "unnecessary complication" or maybe a "one of these days I will understand"