Expression Tree Tutorial - Knowledge Base (KB)

LinqKit System.InvalidCastException When Invoking method-provided expression on member property

Given a simple parent/child class structure. I want to use linqkit to apply a child lambda expression on the parent. I also want the Lambda expression to be provided by a utility method....public class Foo { public Bar Bar { get; set; } } public cl...

Is there a particular reason LinqKit's expander can't pick up Expressions from fields?

I'm using ...LinqKit... library which allows combining expressions on the fly. ...This is a pure bliss for writing Entity Framewok data acess layer because several expressions can optionally be reused and combined, which allows both for readable and effi...

Building a custom predicate to act as a filter using a foreach loop

I need to filter a list of documents by passing them to a custom filter that I'm struggling to ...build dynamically... using a ...foreach... loop :...var mainPredicate = PredicateBuilder.True<Document>(); // mainPredicate is combined to other filters suc...

Unable to refactor using LINQ to Entities and LinqKit / PredicateBuilder

I have been trying to refactor a LINQ expression into a method, and have been running into both the "...Internal .NET Framework Data Provider error 1025...." and "...The parameter 'xyz' was not bound in the specified LINQ to Entities query expression...."...

Conditionally ignore fields with LINQ select

I've been unable to find any examples where you can conditionally exclude fields based off a variable within a select projection in LINQ, see also ...LINQ: Select an object and change some properties without creating a new object.......Let me give some ba...