In LINQ, what is the main difference / usefulness between .Any <> and .Where <> to check if there are records
For example, if I had a Linq to SQL data context or I had ADO.NET Entity Framework entities mapped to a database table and I want to test one client ...
Is there a big difference between:
MyDatabaseContext.Customers.Any(c => c.CustomerId == 3)
MyDatabaseContext.Customers.Where(c => c.CustomerId == 3)
.Any <> - the return type bool
.Where <> - the return type of the IQueryable
EDIT: Corrected question wording after accepting answer from Fredrik Mörk - thanks.
Check the documentation again:
indicating whether at least one item meets the criteria
containing elements matching the criteria
There might be a performance difference in that it
stops as soon as it can determine the result (when it finds a matching element), and
must always loop through all the elements before returning the result. So if you only need to check if there are matching items, it
would be a set method.
. If you are lazy, you can expect
to complete as soon as one satisfying item is found (return true), and
will search for all of them.
If you want to pick one client,
this is what you are looking for.
returns bool. That is, are there any items that match the condition. Use
it if you just want to know if you have items to work with. For example. prefer
Count() == 0
, for example, as the latter can enumerate the entire sequence to see if it is empty or not.
returns a sequence of elements that match a condition.
checks if any elements meet the criteria, i.e. returns
, which means it only has to find the first element, which can be very fast. Whereas it
enumerates all the elements that meet the condition, which means it must iterate over the entire collection.