Dynamic LINQ OrderBy on IEnumerable T IQueryable T

Question

I found an example in the VS2008 Examples for Dynamic LINQ that allows you to use a sql-like string  e g  OrderBy  Name  Age DESC    for ordering  Unfortunately  the method included only works on IQueryable lt T gt   Is there any way to get this functionality on IEnumerable lt T gt

User · Answer

I guess it would work to use reflection to get whatever property you want to sort on:

IEnumerable<T> myEnumerables
var query=from enumerable in myenumerables
          where some criteria
          orderby GetPropertyValue(enumerable,"SomeProperty")
          select enumerable

private static object GetPropertyValue(object obj, string property)
{
    System.Reflection.PropertyInfo propertyInfo=obj.GetType().GetProperty(property);
    return propertyInfo.GetValue(obj, null);
}

Note that using reflection is considerably slower than accessing the property directly, so the performance would have to be investigated.

User · Answer

Just stumbled into this oldie     To do this without the dynamic LINQ library  you just need the code as below  This covers most common scenarios including nested properties   To get it working with IEnumerable lt T gt  you could add some wrapper methods that go via AsQueryable - but the code below is the core Expression logic needed   public static IOrderedQueryable lt T gt  OrderBy lt T gt       this IQueryable lt T gt  source       string property        return ApplyOrder lt T gt  source  property   OrderBy       public static IOrderedQueryable lt T gt  OrderByDescending lt T gt       this IQueryable lt T gt  source       string property        return ApplyOrder lt T gt  source  property   OrderByDescending       public static IOrderedQueryable lt T gt  ThenBy lt T gt       this IOrderedQueryable lt T gt  source       string property        return ApplyOrder lt T gt  source  property   ThenBy       public static IOrderedQueryable lt T gt  ThenByDescending lt T gt       this IOrderedQueryable lt T gt  source       string property        return ApplyOrder lt T gt  source  property   ThenByDescending       static IOrderedQueryable lt T gt  ApplyOrder lt T gt       IQueryable lt T gt  source       string property       string methodName         string   props   property Split           Type type   typeof T       ParameterExpression arg   Expression Parameter type   x        Expression expr   arg      foreach string prop in props               use reflection  not ComponentModel  to mirror LINQ         PropertyInfo pi   type GetProperty prop           expr   Expression Property expr  pi           type   pi PropertyType            Type delegateType   typeof Func lt   gt   MakeGenericType typeof T   type       LambdaExpression lambda   Expression Lambda delegateType  expr  arg        object result   typeof Queryable  GetMethods   Single              method   gt  method Name    methodName                      amp  amp  method IsGenericMethodDefinition                      amp  amp  method GetGenericArguments   Length    2                      amp  amp  method GetParameters   Length    2               MakeGenericMethod typeof T   type               Invoke null  new object    source  lambda        return  IOrderedQueryable lt T gt  result        Edit  it gets more fun if you want to mix that with dynamic - although note that dynamic only applies to LINQ-to-Objects  expression-trees for ORMs etc can t really represent dynamic queries - MemberExpression doesn t support it   But here s a way to do it with LINQ-to-Objects  Note that the choice of Hashtable is due to favorable locking semantics   using Microsoft CSharp RuntimeBinder  using System  using System Collections  using System Collections Generic  using System Dynamic  using System Linq  using System Runtime CompilerServices  static class Program       private static class AccessorCache               private static readonly Hashtable accessors   new Hashtable             private static readonly Hashtable callSites   new Hashtable             private static CallSite lt Func lt CallSite  object  object gt  gt  GetCallSiteLocked              string name                         var callSite    CallSite lt Func lt CallSite  object  object gt  gt  callSites name               if callSite    null                                callSites name    callSite   CallSite lt Func lt CallSite  object  object gt  gt                       Create Binder GetMember                                  CSharpBinderFlags None                                   name                                   typeof AccessorCache                                   new CSharpArgumentInfo                                          CSharpArgumentInfo Create                                          CSharpArgumentInfoFlags None                                           null                                                                  return callSite                     internal static Func lt dynamic object gt  GetAccessor string name                        Func lt dynamic  object gt  accessor    Func lt dynamic  object gt  accessors name               if  accessor    null                                lock  accessors                                         accessor    Func lt dynamic  object gt  accessors name                       if  accessor    null                                                if name IndexOf       gt   0                                string   props   name Split                                   CallSite lt Func lt CallSite  object  object gt  gt    arr                                    Array ConvertAll props  GetCallSiteLocked                               accessor   target   gt                                                                object val    object target                                  for  int i   0  i  lt  arr Length  i                                                                          var cs   arr i                                       val   cs Target cs  val                                                                     return val                                                           else                               var callSite   GetCallSiteLocked name                               accessor   target   gt                                                                return callSite Target callSite   object target                                                                                    accessors name    accessor                                                                    return accessor                       public static IOrderedEnumerable lt dynamic gt  OrderBy          this IEnumerable lt dynamic gt  source           string property                return Enumerable OrderBy lt dynamic  object gt               source               AccessorCache GetAccessor property                Comparer lt object gt  Default              public static IOrderedEnumerable lt dynamic gt  OrderByDescending          this IEnumerable lt dynamic gt  source           string property                return Enumerable OrderByDescending lt dynamic  object gt               source               AccessorCache GetAccessor property                Comparer lt object gt  Default              public static IOrderedEnumerable lt dynamic gt  ThenBy          this IOrderedEnumerable lt dynamic gt  source           string property                return Enumerable ThenBy lt dynamic  object gt               source               AccessorCache GetAccessor property                Comparer lt object gt  Default              public static IOrderedEnumerable lt dynamic gt  ThenByDescending          this IOrderedEnumerable lt dynamic gt  source           string property                return Enumerable ThenByDescending lt dynamic  object gt               source               AccessorCache GetAccessor property                Comparer lt object gt  Default              static void Main                 dynamic a   new ExpandoObject                     b   new ExpandoObject                     c   new ExpandoObject            a X    abc           b X    ghi           c X    def           dynamic   data   new                  new   Y   a                new   Y   b                 new   Y   c                        var ordered   data OrderByDescending  Y X   ToArray            foreach  var obj in ordered                        Console WriteLine obj Y X

User · Answer

you can do it like this for multiple order by IOrderedEnumerable lt JToken gt  sort                          if  query OrderBys 0  IsDESC                                                        sort   jarry OrderByDescending r   gt   string r query OrderBys 0  Key                                                      else                                                       sort   jarry OrderBy r   gt                                   string  r query OrderBys 0  Key                                                       foreach  var item in query OrderBys Skip 1                                                         if  item IsDESC                                                                sort   sort ThenByDescending r   gt   string r item Key                                                              else                                                               sort   sort ThenBy r   gt   string r item Key

User · Answer

Use dynamic linq  just add using System Linq Dynamic   And use it like this to order all your columns   string sortTypeStr    ASC      or DESC string SortColumnName    Age      Your column name query   query OrderBy    SortColumnName   sortTypeStr

User · Answer

You can use this           public List lt Book gt  Books string orderField  bool desc  int skip  int take        var propertyInfo   typeof Book  GetProperty orderField        return  context Books          Where               OrderBy p   gt   desc   propertyInfo GetValue p  null    0           ThenByDescending p   gt  desc   propertyInfo GetValue p  null    0           Skip skip           Take take           ToList

User · Answer

Too easy without any complication    Add using System Linq Dynamic  at the top  Use vehicles   vehicles AsQueryable   OrderBy  Make ASC  Year DESC   ToList

User · Answer

This answer is a response to the comments that need an example for the solution provided by   John Sheehan - Runscope      Please provide an example for the rest of us    in DAL  Data Access Layer     The IEnumerable version     public  IEnumerable lt Order gt  GetOrders                  i use Dapper to return IEnumerable lt T gt  using Query lt T gt             do stuff       return  orders     IEnumerable lt Order gt        The IQueryable version    public IQueryable lt Order gt  GetOrdersAsQuerable                 IEnumerable lt Order gt  qry  GetOrders              use the built-in extension method  AsQueryable in  System Linq namespace         return qry AsQueryable                        Now you can use the IQueryable  version to bind  for example GridView in Asp net and benefit for sorting  you can t sort using IEnumerable version   I used Dapper as ORM and build IQueryable version and utilized sorting in GridView in asp net  so easy

User · Answer

I was trying to do this but having problems with Kjetil Watnedal s solution because I don t use the inline linq syntax - I prefer method-style syntax  My specific problem was in trying to do dynamic sorting using a custom IComparer   My solution ended up like this   Given an IQueryable query like so   List lt DATA  Security  Team gt  teams   TeamManager GetTeams    var query   teams Where team   gt  team ID  lt  10  AsQueryable      And given a run-time sort field argument   string SortField     Set at run-time to  Name    The dynamic OrderBy looks like so   query   query OrderBy item   gt  item GetReflectedPropertyValue SortField      And that s using a little helper method called GetReflectedPropertyValue     public static string GetReflectedPropertyValue this object subject  string field        object reflectedValue   subject GetType   GetProperty field  GetValue subject  null       return reflectedValue    null   reflectedValue ToString               One last thing - I mentioned that I wanted the OrderBy to use custom IComparer - because I wanted to do Natural sorting   To do that  I just alter the OrderBy to   query   query OrderBy item   gt  item GetReflectedPropertyValue SortField   new NaturalSortComparer lt string gt        See this post for the code for NaturalSortComparer

User · Answer

Just stumbled across this question   Using Marc s ApplyOrder implementation from above  I slapped together an Extension method that handles SQL-like strings like   list OrderBy  MyProperty DESC  MyOtherProperty ASC      Details can be found here  http   aonnull blogspot com 2010 08 dynamic-sql-like-linq-orderby-extension html

User · Answer

Convert List to IEnumerable or Iquerable  add using System LINQ Dynamic namespace  then u can mention the property names in comma seperated string to OrderBy Method which comes by default from System LINQ Dynamic

User · Answer

Here s something else I found interesting  If your source is a DataTable  you can use dynamic sorting without using Dynamic Linq  DataTable orders   dataSet Tables  SalesOrderHeader    EnumerableRowCollection lt DataRow gt  query   from order in orders AsEnumerable                                            orderby order Field lt DateTime gt   OrderDate                                            select order  DataView view   query AsDataView    bindingSource1 DataSource   view    reference  http   msdn microsoft com en-us library bb669083 aspx  Using DataSetExtensions   Here is one more way to do it by converting it to a DataView   DataTable contacts   dataSet Tables  Contact        DataView view   contacts AsDataView        view Sort    LastName desc  FirstName asc       bindingSource1 DataSource   view  dataGridView1 AutoResizeColumns

User · Answer

You could add it   public static IEnumerable lt T gt  OrderBy  this IEnumerable lt T gt  input  string queryString          parse the string into property names       Use reflection to get and sort by properties       something like      foreach  string propname in queryString Split               input OrderBy  x   gt  GetPropertyValue  x  propname              I used Kjetil Watnedal s reflection example     The GetPropertyValue function is from Kjetil Watnedal s answer  The issue would be why  Any such sort would throw exceptions at run-time  rather than compile time  like D2VIANT s answer    If you re dealing with Linq to Sql and the orderby is an expression tree it will be converted into SQL for execution anyway

User · Answer

var result1   lst OrderBy a  gt a Name     for ascending order    var result1   lst OrderByDescending a  gt a Name     for desc order

User · Answer

Thanks to Maarten  Query a collection using PropertyInfo object in LINQ  I got this solution   myList OrderByDescending x   gt  myPropertyInfo GetValue x  null   ToList      In my case I was working on a  ColumnHeaderMouseClick   WindowsForm  so just found the specific Column pressed and its correspondent PropertyInfo   foreach  PropertyInfo column in  new Process    GetType   GetProperties          if  column Name    dgvProcessList Columns e ColumnIndex  Name             OR  PropertyInfo column    new Process    GetType   GetProperties   Where x   gt  x Name    dgvProcessList Columns e ColumnIndex  Name  First       be sure to have your column Names matching the object Properties   Cheers

User · Answer

First Install Dynamic  Tools --  NuGet Package Manager --  Package Manager Console  install-package System Linq Dynamic   Add Namespace using System Linq Dynamic   Now you can use OrderBy  Name  Age DESC

User · Answer

Just building on what others have said  I found that the following works quite well   public static IEnumerable lt T gt  OrderBy lt T gt  this IEnumerable lt T gt  input  string queryString        if  string IsNullOrEmpty queryString           return input       int i   0      foreach  string propname in queryString Split                     var subContent   propname Split               if  Convert ToInt32 subContent 1  Trim       0                        if  i    0                  input   input OrderBy x   gt  GetPropertyValue x  subContent 0  Trim                  else                 input     IOrderedEnumerable lt T gt  input  ThenBy x   gt  GetPropertyValue x  subContent 0  Trim                        else                       if  i    0                  input   input OrderByDescending x   gt  GetPropertyValue x  subContent 0  Trim                  else                 input     IOrderedEnumerable lt T gt  input  ThenByDescending x   gt  GetPropertyValue x  subContent 0  Trim                        i               return input

User · Answer

You can convert the IEnumerable to IQueryable   items   items AsQueryable   OrderBy  Name ASC

User · Answer

After a lot of searching this worked for me   public static IEnumerable lt TEntity gt  OrderBy lt TEntity gt  this IEnumerable lt TEntity gt  source                                                       string orderByProperty  bool desc        string command   desc    OrderByDescending     OrderBy       var type   typeof TEntity       var property   type GetProperty orderByProperty       var parameter   Expression Parameter type   p        var propertyAccess   Expression MakeMemberAccess parameter  property       var orderByExpression   Expression Lambda propertyAccess  parameter       var resultExpression   Expression Call typeof Queryable   command                                              new     type  property PropertyType                                               source AsQueryable   Expression                                              Expression Quote orderByExpression        return source AsQueryable   Provider CreateQuery lt TEntity gt  resultExpression

User · Answer

An alternate solution uses the following class interface   It s not truly dynamic  but it works   public interface IID       int ID               get  set           public static class Utils       public static int GetID lt T gt  ObjectQuery lt T gt  items  where T EntityObject  IID               if  items Count      0  return 1          return items OrderByDescending u   gt  u ID  FirstOrDefault   ID   1

User · Answer

I ve stumble this question looking for Linq multiple orderby clauses and maybe this was what the author was looking for  Here s how to do that   var query   pets OrderBy pet   gt  pet Name  ThenByDescending pet   gt  pet Age

[c#] Dynamic LINQ OrderBy on IEnumerable<T> / IQueryable<T>

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