想在一个变量中添加多个变量的数据，数组/列表

Question

I want to add multiple variables data into one variable so that work can come easy.

         string value1 = "bb123";
        string value2 = "bb456";
        string value3 = "bb789";
        string value4 = "bb1011";
        string value5 = "bb736";
        string value6 = "bb66";
        string value7 = "bb67";


        //USERS DATA
        var data  = db.User_Register_Events.Where(x => x.UserTable.User_id == value1).Select(x => x.EventTable.Slot.Slot_Id).ToList();  
           
        var data2 = db.User_Register_Events.Where(x => x.UserTable.User_id == value2).Select(x => x.EventTable.Slot.Slot_Id).ToList();

        var data3 = db.User_Register_Events.Where(x => x.UserTable.User_id == value3).Select(x => x.EventTable.Slot.Slot_Id).ToList();

        var data4 = db.User_Register_Events.Where(x => x.UserTable.User_id == value4).Select(x => x.EventTable.Slot.Slot_Id).ToList();

        var data5 = db.User_Register_Events.Where(x => x.UserTable.User_id == value5).Select(x => x.EventTable.Slot.Slot_Id).ToList();

        var data6 = db.User_Register_Events.Where(x => x.UserTable.User_id == value6).Select(x => x.EventTable.Slot.Slot_Id).ToList();

        var data7 = db.User_Register_Events.Where(x => x.UserTable.User_id == value7).Select(x => x.EventTable.Slot.Slot_Id).ToList();          


        //ALL SLOTS
        List<int> AllSlots = db.Slots.Select(x => x.Slot_Id).ToList();

I want to store all "data, data2,data3,data4,data5,data6,data7"...in one variable so that I can take Except union with "AllData"with AllSlots...

    var AllData = ??????.ToList();

var result = AllSlots.Except(data.Union(AllData)).ToList();

Answer 1

If you query for the same field but with different values then you can just make one single call to your database backend putting all the values to search for in a list and then using this list to filter the field

List<string> values = {"123","456","789","1011","736","66","67"};
var data  = db.User_Register_Events
           .Where(x => values.Contains(x.UserTable.User_id)
           .Select(x => x.EventTable.Slot.Slot_Id).ToList();  
  

However, I have some doubts about your values. They seems to be integers and not strings. If the field UserTable.User_id is an integer then you should query with an integer list, not strings.