Question

I have a comma-separated list of record Ids that I get from a query string. I need to return all the records (from a SQL Server database) with those Ids. What’s the best way to do that in Linq?

I figure that it will ultimately be transformed into a SQL statement of the form “WHERE id IN (1,2,3,…)”, and since that query contains the same comma-separated list that I’m starting with, it seems a shame to un-pack it into an int array and then let Linq convert it back again. But if that’s the only way, then fine.

Answer 1

As you hinted at, it’s easiest to convert it to an array first.

string csv = "1,2,3";
IEnumerable<int> ids = csv.Split(',').Select( str => int.Parse(str));

var records = db.Records.Where( rec => ids.Contains(rec.id) );