如何在LINQ查询语法中执行Max Aggregation？

Question

LINQ method syntax

var methodSyntax = VersionControls.Where(x => !x.Removed).Max(x => x.VersionID);

LINQ query syntax

var querySyntax = from x in VersionControls
                  where !x.Removed
                  // how to do Max Aggregation in LINQ query syntax???
                  select x;

Answer 1

MSDN documentation says about Query Syntax and Method Syntax in LINQ

Query syntax and method syntax are semantically identical, but many people find query syntax simpler and easier to read. Some queries must be expressed as method calls. For example, you must use a method call to express a query that retrieves the number of elements that match a specified condition. You also must use a method call for a query that retrieves the element that has the maximum value in a source sequence.

Query syntax cant express everything that method syntax can

check how to combine them for Min and Max in this answer

var mixedSyntax = (from x in VersionControls
                  where !x.Removed
                  select x).Max(x => x.VersionID);

Answer 2

You have to keep in mind that the Max() method will throw an exception whenever the source collection is empty. That's why I would chain a DefaultIfEmpty(defaultElementValue) just before the Max() for safety issues. This way, ASh 's solution would become :

var mixedSyntax = (from x in VersionControls
                  where !x.Removed
                  select x).DefaultIfEmpty(defaultVersionControlObject)
                           .Max(x => x.VersionID);