Question

I have to Pull all customers whose ids are in the list

I have a list of CustomerID`s

List custidlist=new List{1,2,3….etc.}();

i have to write a linq query to get all customers whose id`s are in the above list

custidlist.

var customers=db.Customers.Where(c=> custidlist.Contains(c.customerid));

Using Contains is not good in performance issue.

Can we use COMPARE OPERATOR LIKE THIS

var customers=db.Customers.Where(c=> custidlist.Compare(c.customerid)); ????

I Heard Compare is best for Performance

Answer 1

Since this is Linq to SQL / Entities your Linq Contains query will be translated to a SQL statement roughly like:

select * from Customers where customerId in (1,2,3)

Not only is your other suggestion not supported, but also you cannot do any better than this SQL performance wise.