Question

I have database

Table room: id,name
Table table: id, id_room
Table WorkPanel: id, id_table, **date**. 

I use (date == date, and WorkPanel have record with table):

var nowWorkPanels = from a in context.WorkPanels where a.date == date select a;

but I do not understand how to make a check at that time and in this room there is a record

Answer 1

You are obviously not showing all of the fields in your tables, but if your navigational properties are set up correctly, your query will look something like:

from wp in context.WorkPanels
where wp.date == date && wp.Table.id_room == roomId
select wp;

or if you want to query by room name:

from wp in context.WorkPanels
where wp.date == date && wp.Table.Room.name == roomName
select wp;

I prefer the more concise method chaining syntax, though:

context.WorkPanels.Where(wp => wp.date == date && wp.Table.id_room == roomId);