dynamic-linq

I have created a dynamic search screen in ASP.NET MVC. I retrieved the field names from the entity through reflection so that I could allow the user to choose which fields they wanted to search on instead of displaying all fields in the view. When the search result is Posted back to the controller, I receive a FormCollection containing the FieldName and the Value. I don't know how many fields are being searched on, and the FormCollection only contains fields that were chosen by the user. I want to be able to now take that field name and apply that to my LINQ statement when I query the database

I'm looking to use LINQ for some searching routines and wanted to have some dynamic where clauses. So, for example, if a user wants to search by city or search by state, I would have a dynamic LINQ Where<> call instead of creating two strongly typed LINQ expressions and then using the appropriate one based on how the user wants to search. So I would like to do this: String criteria="p.City='Pittsburgh'"; //or "p.State='PA'" personData.Where(criteria) instead of personData.Where(p => p.City=="Pittsburgh"); or personData.Where(p => p.State=="PA"); I came across a blog post by Scott Guthrie

How to achieve this using Dynamic Linq Join and Dynamic Linq SelectMany Desired result is in q and q2. q shows combination of aggregates from different levels of grouping in one expression. q2 uses calculated agg from prev levels and generates shorter SQL query. var grp=(db.A as IQueryable).GroupBy("grp","it"); var grp2=grp.Select("new(key as key,new(count() as cnt) as agg)"); foreach(dynamic r in grp2) Console.WriteLine("grp:"+r.key+"\tcnt:"+r.agg.cnt); //foreach(dynamic r in grp) Console.WriteLine(r.Key+"\t"+r.Count()); // throws RuntimeBinderException Console.WriteLine("--------------------

I am building an ASP.Net MVC 3 application with Entity Framework 4. When the two pieces of code below are executed, both variables (query1 and query2) have a return type of System.Data.Objects.ObjectQuery<Asset.Model.Equipment> Query1 uses a direct instance of the ObjectContext, however, Query2 uses a repository pattern, ie, it calls GetEquipment in EquipmentService, which in turns calls the same named method in Equipment Repository. Both the methods in the Service and Repository return IQueryable<Equipment> How, here's my question, how come query2 will only work when I include using System

I need a way to recreate dynamically generated reports at some point in the future. Long story short, I need to store a specific linq query (different for each report) into database and then execute the query with dynamic Linq later on. This is all good, but I can't find a way to convert expression to string. As in: Expression<Func<Product, bool>> exp = (x) => (x.Id > 5 && x.Warranty != false); should become: "Product.Id > 5 && Product.Warranty != false" Is there a way to do that? This may not be the best/most efficient method, but it does work. Expression<Func<Product, bool>> exp = (x) => (x

Using the System.Linq.Dynamic (managed here https://github.com/kahanu/System.Linq.Dynamic ), I am trying to capture the DayOfWeek field found on the DateTime for aggregation purposes using Entity Framework 6 (or greater). Previously asked for something similar, which helped a lot, Dynamic Linq + Entity Framework: datetime modifications for dynamic select Entity Framework supports getting the DayOfWeek using the SqlFunctions.DatePart("dw", datetime?) or we could do something a little more desired using something like DbFunctions.DiffDays(date?, date?). Idea: Getting the DayOfWeek in Linq to

I am trying to do a GroupBy using Dynamic LINQ but have trouble getting it to work. This is some sample code illustrating the problem: List<dtoMyAlbum> listAlbums = new List<dtoMyAlbum>(); for (int i = 0; i < 5000; i++) { dtoMyAlbum album = new dtoMyAlbum { Author = "My Author", BookID = i, CurrSymbol = "USD", Price = 23.23, Shop = i % 3 == 0 ? "TESCO" : "HMV" }; listAlbums.Add(album); } IQueryable<dtoMyAlbum> mydata = listAlbums.AsQueryable(); int count = mydata.Count(); //var mydataGrouped = mydata.GroupBy(a => a.Shop); // <-- this works well (but is not dynamic....) var mydataGrouped =