entity-framework-core

问题 I'm using EntityFrameworkCore 2.0.0-preview2-final and I would like to inject the ApplicationDbContext into Configure method in Startup class. Here's my code: public void Configure(IApplicationBuilder app, IHostingEnvironment env, ILoggerFactory loggerFactory, ApplicationDbContext context) { // rest of my code } but when I run my app I'm getting an error message: System.InvalidOperationException: Cannot resolve scoped service 'ProjectName.Models.ApplicationDbContext' from root provider. Here

问题 I may need help with the title of my question. So here is more detail. In VS2015 I when creating a database using code first migrations, After completing my first migration I was able to view the database in VS by going to the App_Data folder and clicking on the MDF file. It would then open in Server Explorer. However, in VS2017 I no longer have an App_Data folder and when I did my first migration it took a bit of work to find out where my MDF file was located. If you don't know here are the

问题 Is it possible to build a PowerShell cmdlet that incorporate Entity Framework (Core or EF6) for access to an SQL Server database? I've been writing cmdlets in C# for years, but I've gone through a nightmare the last coupla days trying to use Entity Framework in a project due to what appear to be assembly version clashes. Project has three libraries: MyProject.Commands.dll - cmdlets to load MyProject.Lib.dll - common library code used by the cmdlets MyProject.EF.dll - the Entity Framework

问题 Is it possible to build a PowerShell cmdlet that incorporate Entity Framework (Core or EF6) for access to an SQL Server database? I've been writing cmdlets in C# for years, but I've gone through a nightmare the last coupla days trying to use Entity Framework in a project due to what appear to be assembly version clashes. Project has three libraries: MyProject.Commands.dll - cmdlets to load MyProject.Lib.dll - common library code used by the cmdlets MyProject.EF.dll - the Entity Framework

问题 In a .NET Core 2.1 project, I'm using EF Core with Command pattern (using MediatR library) on a SQL Server database. I setup the project to avoid client query evaluation, by using these settings: var phaseOptions = new DbContextOptionsBuilder<PhaseDbContext>().UseSqlServer(configuration.GetConnectionString("PhaseDbContext"), sqlServerOptions => sqlServerOptions .EnableRetryOnFailure( maxRetryCount: 5, maxRetryDelay: TimeSpan.FromSeconds(30), errorNumbersToAdd: null)) .ConfigureWarnings

问题 Entity Framework Core Throwing error while doing update-database Error:- Introducing FOREIGN KEY constraint 'FK_UserRoleRelationship_UserRoels_ParentUserRoleId' on table 'UserRoleRelationship' may cause cycles or multiple cascade paths. Specify ON DELETE NO ACTION or ON UPDATE NO ACTION, or modify other FOREIGN KEY constraints. Could not create constraint or index. public class UserRoleRelationship { [Key] public int Id { get; set; } [Required] public Guid UserRoleRelationshipId { get; set; }

问题 Entity Framework Core Throwing error while doing update-database Error:- Introducing FOREIGN KEY constraint 'FK_UserRoleRelationship_UserRoels_ParentUserRoleId' on table 'UserRoleRelationship' may cause cycles or multiple cascade paths. Specify ON DELETE NO ACTION or ON UPDATE NO ACTION, or modify other FOREIGN KEY constraints. Could not create constraint or index. public class UserRoleRelationship { [Key] public int Id { get; set; } [Required] public Guid UserRoleRelationshipId { get; set; }

问题 Entity Framework Core Throwing error while doing update-database Error:- Introducing FOREIGN KEY constraint 'FK_UserRoleRelationship_UserRoels_ParentUserRoleId' on table 'UserRoleRelationship' may cause cycles or multiple cascade paths. Specify ON DELETE NO ACTION or ON UPDATE NO ACTION, or modify other FOREIGN KEY constraints. Could not create constraint or index. public class UserRoleRelationship { [Key] public int Id { get; set; } [Required] public Guid UserRoleRelationshipId { get; set; }

问题 Entity Framework Core Throwing error while doing update-database Error:- Introducing FOREIGN KEY constraint 'FK_UserRoleRelationship_UserRoels_ParentUserRoleId' on table 'UserRoleRelationship' may cause cycles or multiple cascade paths. Specify ON DELETE NO ACTION or ON UPDATE NO ACTION, or modify other FOREIGN KEY constraints. Could not create constraint or index. public class UserRoleRelationship { [Key] public int Id { get; set; } [Required] public Guid UserRoleRelationshipId { get; set; }

问题 I am having a problem with getting a result when trying to get objects with multiple levels. This is what I am trying to do roughly: _context.Investors.Where(s => s.Id == userId) .Include(c => c.Coins) //only want this if some kind of flag is given by the user. .ThenInclude(ct => ct.CoinType) .Include(c => c.Bricks) //only want this if some kind of flag is given by the user. Essentially I am getting a lot of flags indicating if I should include parts of the object. I got it almost to work.