Check if a Linq IQueryable has an order by applied

How do you feed bits of a LINQ query into a function in LINQ to SQL?

Check out the ...TableView.cs... generic class....In order to apply the Where predicate, it simply utilizes a FuncTEntity, bool> delegate:...//... public TableView(DataContext dataContext, Expression<Func<TEntity, bool>> predicate) { this.table = dataContext.GetTable<TEntity>(); this.baseQuery = table.Where(predicate); this.predicate = ...

Linq to SQL query compilation from a non-trivial IQueryable

At least in my experiments, anything like this is effective:...Expression<Func<DataContext, IQueryable<User>> queryableExpression = GetUsers(); var expressionWithSomeAddedStuff = (DataContext dc) => from u in queryableExpression.Invoke(dc) where ....; var expressionThatCanBeCompiled = expressionWithSomeAddedStuff.Expand(); var foo = CompiledQuery.C...

Partially executing an IQueryable query while leaving the remainder to Linq for Objects

Although the two previous solutions are both correct, it reads better if you convert the IQueryable to IEnumerable using AsEnumerable():...// Using Bob's code... var result = datacontext.Table .Where(x => x.Prop == val) .OrderBy(x => x.Prop2) .AsEnumerable() // <---- anything after this is done by LINQ to Objects .Select(x => new { Co...

How can I apply a filter to a LINQ to SQL expression only if there are results when the filter is applied?

This could work more effectively for your original method:...public static IQueryable<Order> GetOrders(int orderNumber, int? productAreaId, OSDataContext db) { var orders = db.Orders.Where(o => o.OrderNumber == orderNumber && o.Group.GroupTypeId != (int)GroupTypeId.INTERNAL && !o.Deleted); if(productAreaId != null) ...

How may value types in LINQ/lambdas/expression trees be checked at compile time?

You just need to tweak your generic and expression slightly:...public static void SetPropertyThreadSafe<TSource, TPropertyType>(this TSource source, Expression<Func<TSource, TPropertyType>> property, TPropertyType value) ...Next, you give a lambda as follows:...var someObject = new /*Your Object*/ someObject.SetPropertyThreadSafe(x => x.SomeProper...

Unable to cast object of type 'System.Linq.Expressions.UnaryExpression' to type 'System.Linq.Expressions.MemberExpression'

In cases when the input expression is a unary expression, a separate line is required to extract the member....This was just converted from VB.Net, so it may be a little off. Please let me know if there are any little adjustments I need make:...public string GetCorrectPropertyName<T>(Expression<Func<T, Object>> expression) { if (expression.Body...

Build IQueryable.Any with Expression Trees for LINQ queries

Simply calling a static method on the sequence and the lambda expression you defined for the extension method ...Enumerable.Any... or ...Queryable.Any...WHERE... clause. To achieve this, enter ...Expression.Call...:...// for Enumerable.Any<T>(IEnumerable<T>,Predicate<T>) var overload = typeof(Enumerable).GetMethods("Any") ...

Using expression trees to create a custom order by in linq to entities

Your code attempts to produce something similar...Queryable.OrderBy(queryableData.Expression, ExtValue105 => ExtValue105)... I don't see why you would think that would work....According to my understanding of your inquiry, you must dynamically build a phrase like...attribute => attribute.ExtValue105... you may use it to call after that....OrderBy()...

How to apply an expression tree for IQueryable?

Simple ...CreateQuery... Because the provider utilizes the given expression's data source, the call is unsuccessful....You must replace an expression before running it....Enumerable.Empty<string>()... by a gathering using your data:...using System; using System.Collections.Generic; using System.Linq; using System.Linq.Expressions; public class Pro...

Cannot convert from 'System.Linq.Expressions.LambdaExpression' to 'System.Linq.Expressions.Expression

It seems that you are attempting to use expression trees to implement OrderBy dynamically. Try the following instead:...public static IQueryable<T> OrderBy<T>(this IQueryable<T> source, string sortProperty, ListSortDirection sortOrder) { var type = typeof(T); var property = type.GetProperty(sortProperty); var parameter = Expression.Para...