SQL ‘time’ type in Entity Framework Code First
If you want to use Time type in database you will have to use TimeSpan with 24 hour cycle in your application. DateTime is not representation of time.
code-first
Entity Framework loading child collection with sort order
You cannot achieve it directly because neither eager or lazy loading in EF supports ordering or filtering. Your options are: Sort data in your application after you load them from database Execute separate query to load child records. Once you use separate query you can use OrderBy The second option can be used with explicit … Read more
How to configure ProviderManifestToken for EF Code First
If you’re using EF 6 (just released) you have an alternative. Dependency Resolution You can use the new dependency resolution feature to register an implementation of IManifestTokenResolver (described in this preview documentation as IManifestTokenService). This article gives a bit more information on how to use DbConfiguration. The easiest way to use it is like this: … Read more
EF 4.1 Code First error – The entity type SomeType is not part of the model for the current context
It may occur because: DbContext configured with an incorrect connection string The entity specified is actually not mapped in configuration
How do I map TimeSpan with greater than 24 hours to SQL server Code First?
As per my previous question on how to store TimeSpan in SQL I was advised to store it as seconds or ticks etc. In the end I didn’t map the TimeSpan column as there is no equivalent in SQL server. I simply created a 2nd field which converted the TimeSpan to ticks and stored that … Read more
Entity Framework DateTime and UTC
Here is one approach you might consider: First, define this following attribute: [AttributeUsage(AttributeTargets.Property)] public class DateTimeKindAttribute : Attribute { private readonly DateTimeKind _kind; public DateTimeKindAttribute(DateTimeKind kind) { _kind = kind; } public DateTimeKind Kind { get { return _kind; } } public static void Apply(object entity) { if (entity == null) return; var properties = … Read more
Code First Migration with Connection Strings
On the package manager console type: Get-Help Update-Database Relevant part: Update-Database [-SourceMigration <String>] [-TargetMigration <String>] [-Script] [-Force] [-ProjectName <String>] [-StartUpProjectName <String>] [-ConfigurationTypeName <String>] [-ConnectionStringName <String>] [<Com monParameters>] So you can do a Update-Database -ConnectionStringName “MyConnectionString” and it should work like a charm. You also have a MigrateDatabaseToLatestVersion database initializer, if you set it (via Database.SetInitializer()), … Read more
Entity Framework auto incrementing field, that isn’t the Id
You can annotate that property with DatabaseGenerated(DatabaseGeneratedOption.Identity). EF allows only single identity column per table. public class Foo { [Key] public Guid Id { get; set; } [DatabaseGenerated(DatabaseGeneratedOption.Identity)] public long Bar { get; set; } }
Fluent API, many-to-many in Entity Framework Core
EF Core 5.0 RC1+ As of EF Core 5.0 RC1, it’s possible to do this without an explicit join table. EF Core is able to configure a mapping for the many-to-many relationship shown in your question without requiring you to create a PersonClub type. See What’s New in EF Core 5.0, RC1, Many-to-many in the … Read more
How to run Seed() method of Configuration class of migrations
Answering your first question. Create a Migration by running add-migration SeedOnly Clear out all Up() and Down() code generated if there was any pending changes public partial class SeedOnly : DbMigration { public override void Up() { } public override void Down() { } } Then you can Target a Specific Migration by running update-database … Read more