Question

I have “Contains” method but I need a “Not Contains” method. Any suggestions?

var ResultsOfMPD = (from m in engMpdMultiSelect
                    where engMpdMultiItems.Select(o => o.ENG_MPD_MYTECHNIC_TASK_NO).
                    Contains(m.ENG_MPD_MYTECHNIC_TASK_NO)
                    select m);

is there any method like that?

var ResultsOfMPD = (from m in engMpdMultiSelect
                    where engMpdMultiItems.Select(o => o.ENG_MPD_MYTECHNIC_TASK_NO).
                    NOTContains(m.ENG_MPD_MYTECHNIC_TASK_NO)
                    select m);

Answer 1

Use the ! operator, like this:

var ResultsOfMPD = from m in engMpdMultiSelect
                   where !engMpdMultiItems.Select(o => o.ENG_MPD_MYTECHNIC_TASK_NO).
                   Contains(m.ENG_MPD_MYTECHNIC_TASK_NO)
                   select m;

By the way, you don’t need the Select() call.
Instead, you can write

var ResultsOfMPD = from m in engMpdMultiSelect
                   where !engMpdMultiItems.Any(o => o.ENG_MPD_MYTECHNIC_TASK_NO == m.ENG_MPD_MYTECHNIC_TASK_NO)
                   select m;

Or, equivalently,

var ResultsOfMPD = from m in engMpdMultiSelect
                   where engMpdMultiItems.All(o => o.ENG_MPD_MYTECHNIC_TASK_NO != m.ENG_MPD_MYTECHNIC_TASK_NO)
                   select m;