Recent update: 2008-3-21
When using the DataContext object to retrieve and update a database, if I have a property that maps to a column with a different name the UPDATE SQL generated uses the property name as opposed to the name specified in the column attribute. [Table(Name="TestTable")]public class TestObject{ ...
I have a general performance question that needs clarification. Assuming an object graph of Customer, Orders, OrderDetails and assume I am retrieving one customer with 10 orders and each order has 5 orderdetails, how many trips to the database will be required? Is it 3 or 12?Thanks,Dave ...
I have the ability to obtain the underlying sql select statement for a given expression.However, it has parameters instead of hardcoded values. I would need the possibility to get the underlying parameters as well in order to be able to execute the sql statement directly.Northwind db = new ...
Hi, All!I am Ukrainian scientific researcher and developer. I am developing object-oriented network knowledge database which is based on object-oriented database engine. I already implemented .NET 1.1 support. It's very cool that MS devolops declarative object query language for C#. I hope ...
Hi, All!I am Ukrainian scientific researcher and developer. I am developing object-oriented network knowledge database which is based on object-oriented database engine. I already implemented .NET 1.1 support. It's very cool that MS devolops declarative object query language for C#. I hope ...
Is it all features of DLink accept any databases (access, Oracle, DB2, ...) and consider their specificities ? Is it DLink will be include in a future version of .NET framework, or will be a separated framework ? Thanks for your answers.
I installed the C# 3.0 Tech Preview over a normal VS2005 beta 2.While the uninstall from "add/remove programs" appeared to succeed, the IDE is still reporting C# 3.0 as being in use. The ReadMe gives a link to http://www.bellware.net/Bin for a tool to eliminate the IDE support, but this link ...
Hello everybody, I am wondering if it will be made possible to develop other version of LINQ, using data sources other than SQL or XML. I mean, are there any plans for making appropriate APIs public? Tom Jastrzebski
As we're thinking about writing our own ADO provider library (connection, command, reader, adapter etc.) I was just wondering how extensible you are planning to make DLinq and how it will fit in with the current ways of extending ADO.Any pointers to documentation on the subject would be very ...
234 byte By
PeterM at 2008-2-24
Does the LINQ preview for VB9 also includes DLinq for accessing SQL databases? I couldn't find anything and wasn't sure if I had missed something. I looks like Sqlmetal.exe is only available for C# 3.0? Thanks, Peter
1541 byte By
sami at 2008-2-23
Linq is wonderful for my integer programming application. It has eliminated the need for a backend DB, reduced tremendously the amount of code, and the execution time has been cut in half. I am wondering if there is a simpler way of doing CRUD like operations in Linq, especially Updates and ...
3073 byte By
Belsen at 2008-2-22
The Standard Query Operators are great, but at the same time there are ones I'm missing.They are not hard to implement oneself, but maybe they are worth including in standard set.1. Bypublic static IEnumerable<IEnumerable<T>> By<T>(this IEnumerable<T> source, int ...
I'm having troubles with DLINQ.t_parent tableparent_id parent_name1 Avalon2 Indigo3 Whidbey4 Yukont_child tablechild_id parent_id child_name1 1 Chris Anderson2 1 Nate Dunlap3 2 Don Box4 3 Daniel Fernandez5 4 Euan GardenI've not used SQLMETAL tool to generate C# classes from my database. I've ...
Prefacing some words about the focus of this post: I am looking at the features described below having only the maintainability of the resulting code in mind. The assumed situation is having an enterprise project with > 20 developers, internal and external, who built the application, and a ...
381 byte By
SorinD at 2008-2-20
I just wanted to let you know (the LINQ project team) that I'm thrilled by the goodness that LINQ has bring into my (developer) life!I liked C omega, but I love LINQ (and DLinq and XLinq). I love CRUD operations. I love the idea, and the implementation.And congrats for having a preview even ...
1541 byte By
sami at 2008-2-19
Linq is wonderful for my integer programming application. It has eliminated the need for a backend DB, reduced tremendously the amount of code, and the execution time has been cut in half. I am wondering if there is a simpler way of doing CRUD like operations in Linq, especially Updates and ...
I'm having troubles with DLINQ.t_parent tableparent_id parent_name1 Avalon2 Indigo3 Whidbey4 Yukont_child tablechild_id parent_id child_name1 1 Chris Anderson2 1 Nate Dunlap3 2 Don Box4 3 Daniel Fernandez5 4 Euan GardenI've not used SQLMETAL tool to generate C# classes from my database. I've ...
As we're thinking about writing our own ADO provider library (connection, command, reader, adapter etc.) I was just wondering how extensible you are planning to make DLinq and how it will fit in with the current ways of extending ADO.Any pointers to documentation on the subject would be very ...
Is there a way to use LINQ technology to search in a text string?Regular expressions are in my opinion not very intuitive.Something along the lines of From astringSelect WORDS where WORD like '%hello%'orFrom astringSelect WORDS where WORD startswith '<' AND WORD endswith '>'WORD ...
Hi there,I am excited about LINQ. To use it in our applications we need the following:- A an object loaded from several queries should be the same, that is only instanciated once in memory (at least as an option). [This is what typical O/R Mappers do]. However there are variations of this ...
From what I've read about LINQ, it seems like it might indeed be pretty cool. However, when I ran through the LINQ Preview, all of the samples seem very 'Hello World-ish' and I don't have much information yet on how it would affect me directly. Here's what I need, hopefully someone on this ...
477 byte By
Ensoft at 2008-2-15
just curious how this'll be handled. having queries directly embedded in the code is awesome from a type safety standpoint, but what about at runtime?i assume some kind of "on-demand" Compiling for a program like "SQL Query Analyzer" (more aptly named LINQ Query Analyzer) that is dynamically ...
How awkward is the syntax for directly using a foreach statement directly over linq query results: foreach(var x in from e in db.Employees where e.City == "Melbourne" select new{e.FirstName,e.LastName}) { Console.WriteLine(x); } ...
55 byte By
jimCCC at 2008-2-15
Do you intend to include support for Access databases?
234 byte By
PeterM at 2008-2-14
Does the LINQ preview for VB9 also includes DLinq for accessing SQL databases? I couldn't find anything and wasn't sure if I had missed something. I looks like Sqlmetal.exe is only available for C# 3.0? Thanks, Peter
726 byte By
PeterM at 2008-2-14
Can someone please provide me with a little sample for using the count aggregate function with select. I tried the following but got an 'count not declared" compile error: Dim AuthorsCount = Select Count(Author) From Author In AllAuthors Where Author.AuthorSince > "1.1.2005" Class Author ...
Is it all features of DLink accept any databases (access, Oracle, DB2, ...) and consider their specificities ? Is it DLink will be include in a future version of .NET framework, or will be a separated framework ? Thanks for your answers.
170 byte By
Otavio at 2008-2-13
Hi, IMHO it would be nice to see DLink using a Factory Pattern, so I it will be possible to load Oracle, Microsoft or other DLink lib from anyone. 2 cents, please :)
The video example includes a code generation tool that "may" become part of a future Visual Studio to generate classes to represent SQL Tables for DLinq.Someone has already posted a Code Smith template to do something similar.I'm interested in a run time capability that can reference tables by ...
When is Linq shipping in product form? Whidbey? Orcas? Somewhere in between?
I have a general performance question that needs clarification. Assuming an object graph of Customer, Orders, OrderDetails and assume I am retrieving one customer with 10 orders and each order has 5 orderdetails, how many trips to the database will be required? Is it 3 or 12?Thanks,Dave ...
Will use of derived custom class from EntitySet<T> be supported? In our domain we use many strongly typed collection classes with custom business logic on the collection. If we could derive from EntitySet<T> that would probably meet our requirement. Thanks, Dave Foderick
Are there any plans to support inheritance within DLinq, and if so what mappings will be available to persist the objects (particularly the derived types) BTW, great work so far, this is going to greatly simplify DB work Cheers, Steve
I have the following queries/Observations about DLINQ. 1. I could not find any direct way of handling many to many relations. Suppose if User and Role are related by a join table UserRole then I should be able to have a collection of Roles in User and vice versa. Which i think is not ...
When using the DataContext object to retrieve and update a database, if I have a property that maps to a column with a different name the UPDATE SQL generated uses the property name as opposed to the name specified in the column attribute. [Table(Name="TestTable")]public class TestObject{ ...
Does each column that you want to retrieve from the database have to be known at compile time? Suppose that you let your customer create custom columns in the database for some tables. Is it possible to load them into your entity class (in a dictionary for example)? The full list of available ...
Consider this query which implements a join. var q = from c in Customers, o in Orders where c.CustomerId == o.CustomerId group o by new { o.CustomerId, c.CompanyName } into g select new { g.Key.CustomerId, g.Key.CompanyName, NumOrders = g.Group.Count() } As far as I can tell, this implements a ...
Is the VB syntax for XLinq documented anywhere? This document is mostly C#: http://msdn.microsoft.com/VBasic/Future/XLinq%20Overview.docIn specific, what does the Select syntax look like for VB when working with XML? Also, is it implemented in the PDC bits?Thanks. ...
I am intrigued by a comment made by Anders on the LINQ panel, to the effect that LINQ empowers rule and notification systems. Such systems are likely to use custom attributes to capture the rule or trigger expression. This in turn demands that custom attributes should support Func<> as a ...
Hi, is it possible to search for cells values in Cells of a DataGridView using Linq. My target is to search values in a DataGridView without loops.
I'm not sure if this is a problem with my code, or with DLinq, but I'm having trouble with a very basic set of related data. I've included all the data needed to replicate the problem.I've created a new SQL Server 2000 database called LINQTestDB, and within it created two tables:ParentID ...
I've spent a couple minutes reviewing linq, so please forgive me if this is already available. Also, Linq may not be complex enough to need a such query builder and/or a linq query builder might not be feasible, but I thought I'd suggest the following. Query Builder A "query builder" for ...
I just read the specs, play with the toys, and comment where I think I'm either 1) helpful, 2) opinionated, or 3) encountering J2EE hell. Just in case anyone else was under the impression I was involved with LINQ's development. ... though I might be convinced. :)
Classes generated by SQL Metal have attributes placed on them that define their mapping to the underlying database.Every time a changes occur in the mapping (e.g. A column name or size changes), the attributes on the class must be updated and thus must be recompiled.This prevents using those ...
587 byte By
koti at 2008-2-4
Hello guys,I am trying to create my own program using Linq. I am using VS 2005 Beta 2. I have installed the required css compiler for C# 3.0 and also installed the IDE support for C# 3.0. When I compile the program I am getting no errors and the build is successful. When I run the program I am ...
hi thereI am missing the SQL LIKE and IN operators. Are those currently not available or did I not find them?I expected something like var q = from t in something where t.somecolumn like "blah%" select t;andvar q = from t in something where t.idcolumn in (myIDarray) select t;In the samples I ...
Hi all, I've been reading a bit about Linq and WinFS lately. I installed WinFS beta 1 and looked at the examples. It all looks promissing, but WinFS will take about two more years before it will finally be released. I was wondering when the final version Linq will be released. My guess is it ...
How do I move data from IEnumerable<Customer> to Table<Customer> efficiently?The following code results in a runtime error. string connectionString = "Data Source=(local); Initial Catalog=Northwind; Trusted_Connection=Yes";Northwind db = new ...
Hi,I am a system architect for fujitsu australia and we have developped something very close to DLINK in a SQL object DAC. I can't discuss the details of our implemetnation online but I would like to suggest a few things. 1- Being able to automatically map an entity to a table while still ...
I found an apparent bug while working through the DLinq Hands-On Lab. The bug is seen when using a SQL connection string to connect to SQL Server instead of SQL Express and the connection string uses "Data Source" instead of "Server". When I used "Data Source" instead of "Server" I always got ...