linq-to-sql

Error - SqlDateTime overflow. Must be between 1/1/1753 12:00:00 AM and 12/31/9999 11:59:59 PM.

I've been using this piece of code I've written and it's working in this most unclear manner. I wish to insert a row into the database which includes two columns of DateTime: myrow.ApprovalDate = DateTime.Now myrow.ProposedDate = DateTime.Now And yet, when I update the database I receive this error: SqlDateTime overflow. Must be b...

LINQ to SQL not recognizing new associations?

I have two projects using legacy databases with no associations between the tables. In one, if I create associations in the DBML file, I can reference the associations in LINQ like this: From c In context.Cities Where c.city_name = "Portland" _ Select c.State.state_name (assuming I added the link from City.state_abbr to State.state_ab...

WCF, Linq-to-SQL and Parameterized Constructors

How can I get WCF to allow the following? Dim EmployeeID as Integer = 10 Dim emp As New WcfServiceLibrary1.Employee(EmployeeID) Response.write (emp.LastName) Currently I have to do this because I can't figure out a way for WCF to allow for Parameterized Constructors: Dim EmployeeID as Integer = 10 Dim emp As New WcfServiceLibrary1.Em...

Binding a DropDownList in ListView InsertItemTemplate throwing an error

I've got a ListView which binds to a LinqDataSource and displays selected locations. The insert item Contains a dropdownlist that pulls from another LinqDataSource to give all the unselected locations. The problem is that I get the following error when loading the page: Databinding methods such as Eval(), XPath(), and Bind() can only ...

Why can't I cast result of Linq to SQL?

I have a Linq to SQL DataContext with SQL functions into it. While the retrieve object is good, I would like to add a property to the object and same time shortens the object name. So I made an object Reminder that inherits from the Linq to SQL object fnRTHU_ReminderByTaskResult with the property I wanted. public class Reminder : fnRTHU...

LINQ version of TOP PERCENT

Is there a way to perform a top (Take) linq query using percentage? The T-SQL would have been: SELECT TOP 20 PERCENT ... But LINQ seems to only want an int. It seems that I would have to do a count and then a take. Any suggestions? ...

Linq: how to select only the records with the highest date

I have a table 'lasttraces' with the following fields: Id, AccountId, Version, DownloadNo, Date The data looks like this: 28092|15240000|1.0.7.1782|2009040004731|2009-01-20 13:10:22.000 28094|61615000|1.0.7.1782|2009040007696|2009-01-20 13:11:38.000 28095|95317000|1.0.7.1782|2009040007695|2009-01-20 13:10:18.000 28101|15240000|1.0.7....

DataContractSerializer within LINQ to SQL expression?

Hi, I'm new to LINQ expressions and trying to get the following to work: public IQueryable<Models.Powerups.Powerup> GetPowerups(Guid userid) { return from p in dc.Powerups where p.UserId == userid select (Models.Powerups.Powerup) new DataContractSerializer(Type.GetType(p.Type, true)).ReadObject(new XmlTextReader(new StringRea...

Linq To SQL : Error "Database node not found"

I am attempting to experiment with linq to sql using this site as a guide. When running a test I keep getting an error parsing the mapping file I created. The error: System.Xml.Schema.XmlSchemaException : Database node not found. Is the mapping namespace (http://schemas.microsoft.com/linqtosql/mapping/2007) correctly specified? Her...

Using LinqToSql with NLog

Hi I'm writing an .NET 3.5 web application that is using LinqToSql for the basic database stuff. I'd like to use the nLog library for logging. This library can log to a database using good ol' fashioned stored procedures (not that there is anything wrong with that..) but I'd like to use the LingToSql DataContext to log to the database ...

LINQ to SQL: What gives pain?

I decided to use LINQ to SQL in my personal project after hearing lots of goods. Is there any thing I need to taken care before start using it (during initial design)? ...

Will using LINQ to SQL help prevent SQL injection

I'm setting up a public site and the first thing on my mind is SQL injection. I have some text fields I'm saving and am using linq to update/write to the database. Am I safe using linq? This example is creating the user account. Data.MemberRegistrationDataContext context = new MemberRegistrationDataContext(); ...

Generic enforcement

I have a generic class public MyClass<TContext, T> where TContext : DataContext that effectively acts on an instance of another public class MyOtherClass<T> : IEnumerable<T> I want to enforce that the TContext has a Table<T>. Is there a clean way to enforce this? ...

Patterns or techniques for designing a flexible advanced search with Linq Expression Trees

I'm looking to add an "advanced search" capability to my ASP.NET/SQL Server 2005 application. Ideally, I'd like it to be table driven. For example, if my schema changes with the addition of a new column to a table that I want to search, I'd like to have the UI reflect the addition of the new column as a searchable field. I can envisio...

LINQ COUNT on multiple columns

If I have a table with a title column and 3 bit columns (f1, f2, f3) that contain either 1 or NULL, how would I write the LINQ to return the title with the count of each bit column that contains 1? I'm looking for the equivalent of this SQL query: SELECT title, COUNT(f1), COUNT(f2), COUNT(f3) FROM myTable GROUP BY title I'm looking fo...

Querying against LINQ to SQL relationships

Using LINQ to SQL db.Products.Where(c => c.ID == 1).Skip(1).Take(1).ToList(); executes SELECT [t1].[ID], [t1].[CategoryID], [t1].[Name], [t1].[Price], [t1].[Descripti n], [t1].[IsFeatured], [t1].[IsActive] FROM ( SELECT ROW_NUMBER() OVER (ORDER BY [t0].[ID], [t0].[CategoryID], [t0].[Name , [t0].[Price], [t0].[Description], [t0].[...

Linq to SQL Case WHEN in VB.NET?

How do I do a Case WHEN in Linq to SQL (vb.net please). In SQL it would be like this: SELECT CASE WHEN condition THEN trueresult [...n] [ELSE elseresult] END How would I do this in Linq to SQL? ...

Linq To Sql Many-Many Join Table

I am a somewhat experienced Rails developer and I thought I would try out ASP.NET's version of MVC. In doing so I also decided to try Linq->Sql... I am a bit confused about the way Linq->Sql handles joins. A trivial example of my schema is : books: id title categories: id name books_categories: book_id category_id Simply dragging...

How to get a full node path with LINQ to SQL?

Hello, I have a basic hierarchy defined in an SQL table: Id ParentId Name ---------------------- 1 Null Root 2 1 Node1 3 2 Node2 Is there a good LINQ-ish way to get the full path of a node? For example, i want to pass the Id of Node2 and get the full path like Root/Node1/Node2. Thank you in advanc...

Linq to Sql: SubmitChanges() adds more objects to database then I've attached

I have the problem that when calling SubmitChanges() objects that have not been attached to a collection or added using InsertOnSubmit(), are still being inserted into the database. I read online that when assigning an object to a property that represents a foreign key, this object is automatically added to the collection of objects to ...