merge Queryable c# code example
Example: c# merge two lists as queryable
var list3 = list1.Concat(list2);
// or
var list4 = list1.Union(list2);
// Union is a set operation - it returns distinct values.
// Concat simply returns the items from the first sequence followed by the items from the second sequence; the resulting sequence can include duplicate items.
// You can think of Union as Concat followed by Distinct.