SQL-запрос:
SELECT * FROM Table WHERE Column IN (1, 2, 3);
LINQ-Запрос:
int[] needle = new int[] {1,2,3}; var LinqIn = from t in Table where needle.Contains(t.Column) select t
Лямбда:
int[] needle = new int[] {1,2,3}; var LinqIn = Table.Where(t => needle.Contains(t.Column));