How to get max value of a column using Entity Framework?
int maxAge = context.Persons.Max(p => p.Age);
The version above, if the list is empty:
- Returns
null
― for nullable overloads - Throws
Sequence contains no element
exception ― for non-nullable overloads
_
int maxAge = context.Persons.Select(p => p.Age).DefaultIfEmpty(0).Max();
The version above handles the empty list case, but it generates more complex query, and for some reason doesn't work with EF Core.
_
int maxAge = context.Persons.Max(p => (int?)p.Age) ?? 0;
This version is elegant and performant (simple query and single round-trip to the database), works with EF Core. It handles the mentioned exception above by casting the non-nullable type to nullable and then applying the default value using the ??
operator.
If the list is empty I get an exception. This solution will take into account this issue:
int maxAge = context.Persons.Select(p => p.Age).DefaultIfEmpty(0).Max();
Or you can try this:
(From p In context.Persons Select p Order By age Descending).FirstOrDefault
Try this int maxAge = context.Persons.Max(p => p.Age);
And make sure you have using System.Linq;
at the top of your file