If all you want to do with SqlGeography is track points and take advantage of SQL Server 2008’s spatial indices, you can, as others have noted, hide your spatial data column from Linq to SQL and use UDFs or stored procedures. Suppose that you have a table AddressFields that includes Latitude and Longitude fields. Add … Read more
You could use AsEnumerable on the entity, but that would force it to bring back all the columns (even if not used); perhaps instead something like: var q1 = from ent in LinqUtils.GetTable<Entity>() from tel in ent.Telephones.DefaultIfEmpty() select new { Name = ent.FormattedName, Number = (tel == null ? null : ent.Number), Extension = (tel … Read more
First, make sure you are disposing your DataContext when you’re done! He can be a heavy little bastard (edit not heavy to instantiate, but heavy to keep around if you keep using it without disposing); you don’t want old DataContexts hanging around in memory. Second, the DataContext is intended to represent a single logical transaction. … Read more
I have written one for my needs that converts a lookup table of your choice to an enum: Put this code inside an EnumGenerator.ttinclude file: <#@ template debug=”true” hostSpecific=”true” #> <#@ output extension=”.generated.cs” #> <#@ Assembly Name=”System.Data” #> <#@ import namespace=”System.Data” #> <#@ import namespace=”System.Data.SqlClient” #> <#@ import namespace=”System.IO” #> <#@ import namespace=”System.Text.RegularExpressions” #> <# … Read more
You can take advantage of the new Metadata functionality in the System.ComponentModel.DataAnnotations which will allow us to separate the MetaData from the existing domain model. For example: [MetadataType (typeof (BookingMetadata))] public partial class Booking { // This is your custom partial class } public class BookingMetadata { [Required] [StringLength(15)] public object ClientName { get; set; … Read more
This should do the trick var query = from a in context.TableA from b in context.TableB .Where(x => x.TableA_Id == a.Id) .OrderBy(x => x.Value) .Take(10) where a.Key >= 0 && a.Key <= 999 select new { a.Key, b.Value, };
Use @@identity instead of scope_identity(). While scope_identity() returns the last created id in the current scope, @@identity returns the last created id in the current session. The scope_identity() function is normally recommended over the @@identity field, as you usually don’t want triggers to interfer with the id, but in this case you do.
Rick Strahl has a nice article about your options: http://www.west-wind.com/weblog/posts/246222.aspx. See also: LINQ to SQL – where does your DataContext live?. You may want a slightly different strategy for each type of deployment – web, desktop, windows service… Summarized, your options are: Global DataContext – dangerous in multi-threaded environments (including web apps). Remember that instance … Read more
Instead of putting it into an own list by calling ToList() or ToArray() i would prefer to use AsEnumerable(). Additionally like the others you should try OrderByDescending() Instead of Count() i would use Any().
Collections are not generally very useful for DAL returns, because a collection does not implicitly guarantee order. It’s just a bucket of items. An IList, on the other hand, does implicitly guarantee order. So we’re down to IEnumerable or IList. The next question would be: is the List object “live”? i.e., is it connected to … Read more