Unless you're actually trying to create a new projection, you can simply avoid using a select
until the end.
List<Categories> myCats = (from city in myCities
where city.CityName == myCityName
//select city
from ids in city.IDs
where ids != 4
select ids).ToList();
I personally like breaking up my queries into pieces:
var matchingCities = from city in myCities
where city.CityName == myCityName
select city;
var matchingCityIds = (from city in matchingCities
from id in city.IDs
select id).ToList();
This approach has two main advantages:
- The variable names give you automatic "documentation", allowing other developers to see what the intent of each transformation is.
- It's easier to debug because you can step over each transformation and verify that you got the results you wanted.
If you really do need to follow one select by another, though, you can use the into
keyword to chain the queries together.
List<Categories> myCats = (from city in myCities
where city.CityName == myCityName
// Not typically recommended
select city.IDs into cityIDs
from id in cityIDs
where id != 4
select id).ToList();