ef-core-2.1

问题 I am trying to seed an user entity in my database. The User entity has an owend property EmailPermissions . When I run the command dotnet ef migrations add Initial; I get the error The seed entity for entity type 'User' cannot be added because it has the navigation 'EmailPermissions' set. To seed relationships you need to add the related entity seed to 'EmailPermissions' and specify the foreign key values {'UserId'}. but since EmailPermissions is an owned entity I didn't give it an explicit

问题 In my app I am trying to follow DDD whilst modelling a simple fund account. The classes are FundAccount public Guid Id { get; set; } private ICollection<AccountTransaction> _transactions = new List<AccountTransaction>(); public IReadOnlyCollection<AccountTransaction> Transactions => _transactions .OrderByDescending(transaction => transaction.TransactionDateTime).ToList(); AccountTransaction public Guid Id { get; set; } public decimal Amount { get; set; ) I am trying to retrieve the fund

问题 I have researched this and always found examples like this: var blogs = context.Blogs .FromSql("SELECT * FROM dbo.Blogs") .ToList(); The problem is, I don't want to run my raw SQL on the Blogs table. Basically, I want to implement an interface like this: bool ExecuteNonSafeSql( string connectionString, string sql); Is there a way to do that with DbContext? 回答1: At the time of writing (EF Core 2.1), there is no way to execute arbitrary secuence returning SQL command. Only entity types and

问题 I have researched this and always found examples like this: var blogs = context.Blogs .FromSql("SELECT * FROM dbo.Blogs") .ToList(); The problem is, I don't want to run my raw SQL on the Blogs table. Basically, I want to implement an interface like this: bool ExecuteNonSafeSql( string connectionString, string sql); Is there a way to do that with DbContext? 回答1: At the time of writing (EF Core 2.1), there is no way to execute arbitrary secuence returning SQL command. Only entity types and

问题 I'm trying to find a way to get a List of all of the entity models in my DbContext. For instance, if I have two models called Customer and Invoice defined in C# which through code-first I created EF entities and a database, how do I now query the DbContext to get a List that has Customer and Invoice in it -- i.e., all of the entities in that context? I want to be able to call a method that returns a List of all the entities -- not the data, just a list of the entities. It seems to me this

问题 I'm using ASP.NET Core 2.2 and I'm using model binding for uploading file. This is my UserViewModel public class UserViewModel { [Required(ErrorMessage = "Please select a file.")] [DataType(DataType.Upload)] public IFormFile Photo { get; set; } } This is MyView @model UserViewModel <form method="post" asp-action="UploadPhoto" asp-controller="TestFileUpload" enctype="multipart/form-data"> <div asp-validation-summary="ModelOnly" class="text-danger"></div> <input asp-for="Photo" /> <span asp

问题 I'm using Entity Framework Core 2.1.2 with lazy loading enabled and am performing a query using AsNoTracking. I'm using Include to bring in my navigation property (a collection). If all my entities have at least one child in their collection then it all works fine. However, if any of my entities have no children then I get an error: System.InvalidOperationException: Error generated for warning 'Microsoft.EntityFrameworkCore.Infrastructure.DetachedLazyLoadingWarning: An attempt was made to

问题 Looking forward to build a framework, (No repository pattern to working with DbSets directly) to autopopulate Created and last modified automatically, rather than spitting out these codes through out code base. Could you point me out in right direction how to achieve it. In past I tried populating these in constructors, however that seems like a nasty code and every time we pull up somting from database EF change tracking will mark the entity as modified. .ctor() { Created = DateTime.Now;

问题 I am using ASP.Net Core 2.1 with EF Core 2.1 While running any Migration from PMC, I am getting the below error Value cannot be null. Parameter name: connectionString This is how my Context class looks like public class MyAppContextFactory : IDesignTimeDbContextFactory<MyAppContext> { private readonly string _dbConnection; public MyAppContextFactory() { } public MyAppContextFactory(string dbConnection) : this() { _dbConnection = dbConnection; } public MyAppContext CreateDbContext(string[]

问题 I am using ASP.Net Core 2.1 with EF Core 2.1 While running any Migration from PMC, I am getting the below error Value cannot be null. Parameter name: connectionString This is how my Context class looks like public class MyAppContextFactory : IDesignTimeDbContextFactory<MyAppContext> { private readonly string _dbConnection; public MyAppContextFactory() { } public MyAppContextFactory(string dbConnection) : this() { _dbConnection = dbConnection; } public MyAppContext CreateDbContext(string[]