How to load value of last employeeid + 1 in add action - asp.net-mvc

Question

I have controller name emp have action add
i need when action add view loaded display last value increased by one in
employeeid textbox .
meaning suppose i have in employee table employeeid value 1 then when action add
view loaded employeeid must have 2 .
so that how to do that please ?
in action what i write
[httpget]
Hide Copy Code
public IActionResult Create()
{
what i write here
}
on view add
what i write here
<div class="form-group">
<label asp-for="EmployeeId" class="control-label"></label>
<input asp-for="EmployeeId" class="form-control" />
<span asp-validation-for="EmployeeId" class="text-danger"></span>
</div>
What I have tried:
var results = _context.GetAll().Where(Employee => Employee.EmployeeId> Employee.EmployeeId).OrderBy(Employee => Employee.EmployeeId).FirstOrDefault();
and i pass model to view
<form asp-action="Create">
<div asp-validation-summary="ModelOnly" class="text-danger"></div>
<div class="form-group">
<label asp-for="EmployeeId" class="control-label"></label>
<input asp-for="EmployeeId" class="form-control" />
<span asp-validation-for="EmployeeId" class="text-danger"></span>
</div>
<div class="form-group">
<label asp-for="BranchCode" class="control-label"></label>
<input asp-for="BranchCode" class="form-control" />
<span asp-validation-for="BranchCode" class="text-danger"></span>
</div>
<div class="form-group">
<label asp-for="EmployeeName" class="control-label"></label>
<input asp-for="EmployeeName" class="form-control" />
<span asp-validation-for="EmployeeName" class="text-danger"></span>
</div>
<div class="form-group">
<label asp-for="EmployeeAge" class="control-label"></label>
<input asp-for="EmployeeAge" class="form-control" />
<span asp-validation-for="EmployeeAge" class="text-danger"></span>
</div>
<div class="form-group">
<label asp-for="JoinDate" class="control-label"></label>
<input asp-for="JoinDate" class="form-control" />
<span asp-validation-for="JoinDate" class="text-danger"></span>
</div>
<div class="form-group">
<label asp-for="BirthDate" class="control-label"></label>
<input asp-for="BirthDate" class="form-control" />
<span asp-validation-for="BirthDate" class="text-danger"></span>
</div>
<div class="form-group">
<div class="checkbox">
<label>
<input asp-for="Active" /> #Html.DisplayNameFor(model => model.Active)
</label>
</div>
</div>
<div class="form-group">
<input type="submit" value="Create" class="btn btn-default" />
</div>
</form>
</div>
</div>

Answer 1

Please don't use .GetAll() , it'll be cause for performance issue. it means you are loading all employee records to the application side, then you are actually querying to loaded employee data. just think about if you have 50K+ employee. So, you have to use LINQ IQueryable extension methods, which will generate the SQL operation based on your design query.
Help Link:.NET Entity Framework - IEnumerable VS. IQueryable
Please Try This, if you want to do some other expressions.
context.Employee.Select(x => x.EmployeeId).DefaultIfEmpty(0).Max()+1

Answer 2

If your model have property EmployeeId then set this value to it like below.
public IActionResult Create()
{
var model = new Employee();
model.EmployeeId = _context.GetAll().Max(Employee => Employee.EmployeeId).FirstOrDefault() + 1;
return View(model);
}
Or if you don't have Model to pass to View then use ViewBag.
ViewBag["maxEmployeeId"] = _context.GetAll().Max(Employee => Employee.EmployeeId).FirstOrDefault() + 1;