C# Linq 比较两个表的查询

Question

I want linq c# query to compare two tables and list unmatched record from table 1

Answer 1

List<MyClass> Unmatched = new List<MyClass>();

foreach (var row in Table_A)
{
if (Table_B.Count(x => x.ID == row.ID) == 0)
Unmatched.Add(row);
}

Something like that?

It will only check Unmached Table1 to Table2. It doesn't check Table2 to Table1.

We need more details.

EDIT

Answer 2

The last line of code compares the elements of two lists and with ! Contains keep only the unmatched elements of the first list and added to the new Unmathced list:

List<string> table_1 = new List<string>() { "panos", "mitsos", "alex", "niki" };

List<string> table_2 = new List<string>() { "panos", "mitsos", "alexandros", "maria" };

List<string> UnmatchedList= new List<string>();

UnmatchedList = table_1.Where(x => !table_2.Contains(x)).ToList();