How to remove child one to many related records in EF code first database?
In EF6 a faster way to do the operation is… context.Children.RemoveRange(parent.Children)
code-first
Entity Framework Code First Many to Many Setup For Existing Tables
Remove your Essence2EssenceSet model class. If junction table contains only keys of related entities participating in many-to-many relations it is not needed to map it as entity. Also make sure that your fluent mapping of many-to-many relations specifies schema for table: mb.Entity<Essence>() .HasMany(e => e.EssenceSets) .WithMany(set => set.Essences) .Map(mc => { mc.ToTable(“Essence2EssenceSet”, “Com”); mc.MapLeftKey(“EssenceID”); mc.MapRightKey(“EssenceSetID”); … Read more
Change foreign key constraint naming convention
You can implement a custom sql generator class derived from SqlServerMigrationSqlGenerator from System.Data.Entity.SqlServer namespace: public class CustomSqlGenerator : SqlServerMigrationSqlGenerator { protected override void Generate(AddForeignKeyOperation addForeignKeyOperation) { addForeignKeyOperation.Name = getFkName(addForeignKeyOperation.PrincipalTable, addForeignKeyOperation.DependentTable, addForeignKeyOperation.DependentColumns.ToArray()); base.Generate(addForeignKeyOperation); } protected override void Generate(DropForeignKeyOperation dropForeignKeyOperation) { dropForeignKeyOperation.Name = getFkName(dropForeignKeyOperation.PrincipalTable, dropForeignKeyOperation.DependentTable, dropForeignKeyOperation.DependentColumns.ToArray()); base.Generate(dropForeignKeyOperation); } private static string getFkName(string primaryKeyTable, string foreignKeyTable, params string[] … Read more
How do I remove underscore of foreign key fields in code first by convention
I finally found an answer for this, by writing a custom convention. This convention works in EF 6.0 RC1 (code from last week), so I think it’s likely to continue to work after EF 6.0 is released. With this approach, the standard EF conventions identify the independent associations (IAs), and then create the EdmProperty for … Read more
Nullable property to entity field, Entity Framework through Code First
Just omit the [Required] attribute from the string somefield property. This will make it create a NULLable column in the db. To make int types allow NULLs in the database, they must be declared as nullable ints in the model: // an int can never be null, so it will be created as NOT NULL … Read more
How do I use Entity Framework in Code First Drop-Create mode?
Use DropCreateDatabaseAlways initializer for your database. It will always recreate database during first usage of context in app domain: Database.SetInitializer(new DropCreateDatabaseAlways<YourContextName>()); Actually if you want to seed your database, then create your own initializer, which will be inherited from DropCreateDatabaseAlways: public class MyInitializer : DropCreateDatabaseAlways<YourContextName> { protected override void Seed(MagnateContext context) { // seed database … Read more
How to disable migration in Entity Framework 4.3.1?
If you don’t want to use migrations but in the same time you want EF to create database for you, you just need to set correct database initializer: Database.SetInitializer<YourContextType>(new CreateDatabaseIfNotExists<YourContentType>());
Entity Framework Code First Date field creation
Try to use ColumnAttribute from System.ComponentModel.DataAnnotations (defined in EntityFramework.dll): [Column(TypeName=”Date”)] public DateTime ReportDate { get; set; }
Entity Framework Database.SetInitializer simply not working
The database will only be created when you actually use the context. If you have overridden the Seed method in your initializer as follows: protected override void Seed(MyContext context){…} The Seed code will only run when you use an instance of MyContext. That is why it works when you use var ctx = new MyContext(); … Read more
EF4 Code First: how to add a relationship without adding a navigation property
I believe you always need navigation property on at least one side when using code-first. Then you will be able to map it: public class User { public string UserId { get; set; } public string PasswordHash { get; set; } public bool IsDisabled { get; set; } public DateTime AccessExpiryDate { get; set; } … Read more