How to: Find the Maximum Value in a Numeric Sequence (LINQ to SQL)
Use the Max operator to find the highest value in a sequence of numeric values.
Example
The following example finds the latest date of hire for any employee.
If you run this query against the sample Northwind database, the output is: 11/15/1994 12:00:00 AM.
Dim latestHireDate = Aggregate emp In db.Employees _
Into Max(emp.HireDate)
Console.WriteLine(latestHireDate)
System.Nullable<DateTime> latestHireDate =
(from emp in db.Employees
select emp.HireDate)
.Max();
Console.WriteLine(latestHireDate);
The following example finds the most units in stock for any product.
If you run this example against the sample Northwind database, the output is: 125.
Dim maxUnitsInStock = Aggregate prod In db.Products _
Into Max(prod.UnitsInStock)
Console.WriteLine(maxUnitsInStock)
System.Nullable<Int16> maxUnitsInStock =
(from prod in db.Products
select prod.UnitsInStock)
.Max();
Console.WriteLine(maxUnitsInStock);
The following example uses Max to find the Products that have the highest unit price in each category. The output then lists the results by category.
Dim maxQuery = From prod In db.Products() _
Group prod By prod.CategoryID Into grouping = Group _
Select CategoryID, _
MostExpensiveProducts = _
(From prod2 In grouping _
Where prod2.UnitPrice = _
grouping.Max(Function(prod3) prod3.UnitPrice))
For Each grp In maxQuery
Console.WriteLine(grp.CategoryID)
For Each listing In grp.MostExpensiveProducts
Console.WriteLine(listing.ProductName)
Next
Next
var maxQuery =
from prod in db.Products
group prod by prod.CategoryID into grouping
select new
{
grouping.Key,
MostExpensiveProducts =
from prod2 in grouping
where prod2.UnitPrice == grouping.Max(prod3 =>
prod3.UnitPrice)
select prod2
};
foreach (var grp in maxQuery)
{
Console.WriteLine(grp.Key);
foreach (var listing in grp.MostExpensiveProducts)
{
Console.WriteLine(listing.ProductName);
}
}
If you run the previous query against the Northwind sample database, your results will resemble the following:
1
Côte de Blaye
2
Vegie-spread
3
Sir Rodney's Marmalade
4
Raclette Courdavault
5
Gnocchi di nonna Alice
6
Thüringer Rostbratwurst
7
Manjimup Dried Apples
8
Carnarvon Tigers
See Also
Concepts
Downloading Sample Databases (LINQ to SQL)