NLinq

New Post: Datasource

lmayne — Wed, 23 Jul 2008 15:19:59 GMT

Is it possible to set the datasource of a gridview directly to an NLinq query? e.g.

Dim nlqQuery As New NLinqQuery("from u in users join n in notes on u.UserId equals n.UserId " & _
"select new { n.DateCreated, u.Name, n.Details }")
Dim nlqMem As New LinqToMemory(nlqQuery)
nlqMem.AddSource("users", colUsers)
nlqMem.AddSource("notes", colNotes)
Me.gvwNotes.DataSource = nlqMem. (?)

For a gridview with named columns, like:

<asp:GridView ID="gvwNotes" runat="server" AutoGenerateColumns="False">
<Columns>
<asp:BoundField HeaderText="Date added" DataField="DateCreated" />
<asp:BoundField HeaderText="Author" DataField="Name" />
<asp:BoundField DataField="Details" />
</Columns>
</asp:GridView>

I've tried using .Enumerator() and .Enumerator(Of T) but the first claims that there is not a property called DateCreated on the datasource, and the second doesn't seem to know how to cast the nlinq variant into another collection type.
.List also doesn't seem to work by default. Any ideas?

CLOSED ISSUE: Joins are not working on RC

sebastienros — Thu, 13 Mar 2008 17:24:10 GMT

The resultset I got from the Join example is different from that expected. I get:

{ Firstname = Bill; City = Redmon; }
{ Firstname = Bill; City = Redmon; }
{ Firstname = Bill; City = Redmon; }

which should have actually been:

{ Firstname = Bill; City = Redmon; }
{ Firstname = Bill; City = Boston; }
{ Firstname = Cindy; City = New York; }
Comments: This has been corrected in RC 2.

NEW POST: Documentation/Help?

sebastienros — Thu, 13 Mar 2008 17:04:58 GMT

Do you still have this issue with the latest release ?

CREATED RELEASE: NLinq Release Candidate 2 (janv. 20, 2008)

Sun, 20 Jan 2008 09:15:15 GMT

- Corrected a bug on logical joins

CREATED ISSUE: Joins are not working on RC

moggoly — Fri, 18 Jan 2008 10:50:25 GMT

UPDATED RELEASE: NLinq Release Candidate (janv. 15, 2008)

Tue, 15 Jan 2008 08:54:10 GMT

- Added sub queries management
- Added "null" keyword
- Added unit tests to common scenarios
- Optimized reflection performance

RELEASED: NLinq Release Candidate (Jan 15, 2008)

Tue, 15 Jan 2008 08:54:10 GMT

- Added sub queries management
- Added "null" keyword
- Added unit tests to common scenarios
- Optimized reflection performance

UPDATED RELEASE: NLinq Release Candidate (janv. 15, 2008)

Tue, 15 Jan 2008 08:48:31 GMT

- Added sub queries management
- Added "null" keyword
- Added unit tests to common scenarios

UPDATED RELEASE: Release Candidate (janv. 15, 2008)

Tue, 15 Jan 2008 08:48:09 GMT

- Added sub queries management
- Added "null" keyword
- Added unit tests to common scenarios

CREATED RELEASE: Releas Candidate (janv. 15, 2008)

Tue, 15 Jan 2008 08:47:45 GMT

- Added sub queries management
- Added "null" keyword
- Added unit tests to common scenarios

UPDATED RELEASE: NLinq Beta 2 (nov. 14, 2007)

Wed, 14 Nov 2007 19:46:04 GMT

Corrected a bug on empty relationship joins
Corrected a bug on escaping characters

RELEASED: NLinq Beta 2 (Nov 14, 2007)

Wed, 14 Nov 2007 16:28:49 GMT

Corrected a bug on empty relationship joins
Corrected a bug on escaping characters

CREATED RELEASE: NLinq Beta 2 (nov. 14, 2007)

Wed, 14 Nov 2007 16:28:49 GMT

Corrected a bug on empty relationship joins
Corrected a bug on escaping characters

NEW POST: Documentation/Help?

pianomanjh — Sat, 20 Oct 2007 00:59:14 GMT

I am hoping to use your fantastic library for a rules engine implementation. Couple questions. First, is there any additional documentation. The samples are nice, but just seem to scratch the surface.
Second, can anyone help me with the following queries?

// throws null ref. How to compare string to Empty?
NLinqQuery query = new NLinqQuery(
@" from c in contributions
where c.Contact.LastName == '' && c.Contact.FirstName == '' && c.Amount == 100
select new RulesEngineNLINQ.Individual { c.Contact.LastName }");

// How to perform joins to get a query like this?
NLinqQuery query = new NLinqQuery(
@" from c in contributions.Contact.Adresses
where c.Street == 'Blah'
select new RulesEngineNLINQ.Address()");

UPDATED WIKI: Home

sebastienros — Fri, 19 Oct 2007 11:27:27 GMT

Project Description

NLinq is a framework focusing on reimplementing the Linq functionnalities in Visual Studio .Net 2003 and Visual Studio 2005 (C# & VB .Net) by providing a Linq grammar parser and a "Linq To Objects" execution environment. With NLinq you can take advantage of major C# 3.0 features right now, without requiring it.

See some samples or how NLinq handles some of the Linq 101 Samples.
You can also read the Skeptical Faq for common questions about NLinq.

Sample Usage

The goal is to implement this query: "Get all the instance methods on System.String, ordered by name and grouped into overloads, each with the name of the overloaded member and the number of overloads."

            query = new NLinqQuery(
                @"  from m in methods
                    where !m.IsStatic
                    orderby m.Name
                    group m by m.Name into g
                    select new { MethodName = g.Key, Overloads = g.Count() }");
 
            linq = new LinqToMemory(query);
            linq.AddSource("methods", typeof(string).GetMethods());
 
            foreach (object o in linq.Enumerate())
            {
                Console.WriteLine(o);
            }

Result

{ MethodName = Clone; Overloads = 1; }
{ MethodName = CompareTo; Overloads = 2; }
{ MethodName = Contains; Overloads = 1; }
{ MethodName = CopyTo; Overloads = 1; }
{ MethodName = EndsWith; Overloads = 3; }
{ MethodName = Equals; Overloads = 3; }
{ MethodName = get_Chars; Overloads = 1; }
{ MethodName = get_Length; Overloads = 1; }
{ MethodName = GetEnumerator; Overloads = 1; }
{ MethodName = GetHashCode; Overloads = 1; }
{ MethodName = GetType; Overloads = 1; }
{ MethodName = GetTypeCode; Overloads = 1; }
{ MethodName = IndexOf; Overloads = 9; }
{ MethodName = IndexOfAny; Overloads = 3; }
{ MethodName = Insert; Overloads = 1; }
{ MethodName = IsNormalized; Overloads = 2; }
{ MethodName = LastIndexOf; Overloads = 9; }
{ MethodName = LastIndexOfAny; Overloads = 3; }
{ MethodName = Normalize; Overloads = 2; }
{ MethodName = PadLeft; Overloads = 2; }
{ MethodName = PadRight; Overloads = 2; }
{ MethodName = Remove; Overloads = 2; }
{ MethodName = Replace; Overloads = 2; }
{ MethodName = Split; Overloads = 6; }
{ MethodName = StartsWith; Overloads = 3; }
{ MethodName = Substring; Overloads = 2; }
{ MethodName = ToCharArray; Overloads = 2; }
{ MethodName = ToLower; Overloads = 2; }
{ MethodName = ToLowerInvariant; Overloads = 1; }
{ MethodName = ToString; Overloads = 2; }
{ MethodName = ToUpper; Overloads = 2; }
{ MethodName = ToUpperInvariant; Overloads = 1; }
{ MethodName = Trim; Overloads = 2; }
{ MethodName = TrimEnd; Overloads = 1; }
{ MethodName = TrimStart; Overloads = 1; }

Original idea for this query: LukeH http://blogs.msdn.com/lukeh/archive/2007/03/31/in-memory-query-with-c-2-0-and-c-3-0.aspx

People behind NLinq

NLinq is a project managed by the people of Evaluant (http://www.evaluant.com) and is a part of its R&D developments.

CREATED RELEASE: NLinq Beta (oct. 10, 2007)

Fri, 19 Oct 2007 10:14:09 GMT

Beta release
* Changed namespaces to Evaluant.NLinq.*
* Assemblies are signed
* Added Enumerate(), Evaluate() and List() methods

UPDATED WIKI: Home

sebastienros — Fri, 07 Sep 2007 05:44:55 GMT

Project Description

Sample Usage

            query = new NLinqQuery(
                @"  from m in methods
                    where !m.IsStatic
                    orderby m.Name
                    group m by m.Name into g
                    select new { MethodName = g.Key, Overloads = g.Count() }");
 
            linq = new LinqToMemory(query);
            linq.AddSource("methods", typeof(string).GetMethods());
 
            foreach (object o in linq.Evaluate<IEnumerable>())
            {
                Console.WriteLine(o);
            }

People behind NLinq

NLinq is a project managed by the people of Evaluant (http://www.evaluant.com) and is a part of its R&D developments.

UPDATED WIKI: Skeptical Faq

sebastienros — Thu, 06 Sep 2007 07:03:19 GMT

Your project is useless, Linq works on .NET 2.0 !

Yes, NLinq is useless. Well, at least for people programming their applications with Visual Studio .NET 2008. For people using a previous version it might be usefull. There are also some scenarios where this could answer the Linq "dynamic" model flow (c.f. bellow).

It's not Linq, you even don't have intellisense !

Yes, NLinq is not as powerfull as Linq. Actually we are not stating that NLinq is better than Linq, even not as good. The Linq language is a subset of C# and VB.NET in Visual Studio 2008. Thus we can't have those keywords in other versions, which makes it impossible not to use strings to represent Linq queries.

How is the performance with NLinq ?

Bad ! And maybe even more than Linq has bad performances. You can't "browse" objects in a generic way with the same performance you browse them specifically. I mean if you want "performance", just don't use Linq, even C#, use assembler. You should ask yourself what time you judge convenient for a specific query, then try it. I can say that most of the time you won't say it's too slow for the advantage it offers.
If you want better performance, some other projects add indexing to "Linq To Objects" (c.f. http://www.codeplex.com/i4o).

So what should I use NLinq for ?

Fun ! And maybe some more interesting things. If you are using earlier versions of Visual Studio .NET the answer is the same as why you should use Linq. But there are some scenarios where NLinq can be helpful even for Visual Studio .NET 2008 users. For instance if you need to set mathematical formulas or object queries outside the application, i.e. in configuration files or the database, even the real Linq can't help you. Then NLinq beats it ! Yeah !!!!

UPDATED WIKI: Skeptical Faq

sebastienros — Thu, 06 Sep 2007 06:59:58 GMT

Your project is useless, Linq works on .NET 2.0 !

It's not Linq, you even don't have intellisense !

How is the performance with NLinq ?

Bad ! And maybe even more than Linq has bad performances. You can't "browse" objects in a generic way with the same performance you brose hem specifically. I mean if you want "performance", just don't use Linq, even C#, use assembler. You should ask yourself what time you judge convenient for a specific query, then try it. I can say that most of the time you won't say it's too slow for the advantage it offers.
If you want better performance, some other projects add indexing to "Linq To Objects" (c.f. http://www.codeplex.com/i4o).

So what should I use NLinq for ?

Fun ! And maybe some more interesting things. If you are using earlier version of Visual Studio .NET the answer is the same as why you should use Linq. But there are some scenarios where NLinq can be helpful even for Visual Studio .NET 2008 users. For instance if you need to set mathematical formulas or object queries outside the application, i.e. in configuration files or the database, even the real Linq can't help you. Then NLinq beats it ! Yeah !!!!

UPDATED WIKI: Skeptical Faq

sebastienros — Thu, 06 Sep 2007 06:56:39 GMT

Your project is useless, Linq works on .NET 2.0 !

Yes, NLinq is useless. Well, at least for people programming their applications with Visual Studio .NET 2008. For people using a previous version it might be usefull. Their are also some scenarios where this could answer the Linq "dynamic" model flow (c.f. bellow).