ef-code-first

问题 What is the minimal permission needed on a sql server user/login for it to be able to run entity framework code first database migrations? I naively would have thought that a user with the roles db_datareader, db_datawriter, Grant Alter on the Schema and Grant Create Table would be permissive enough. 回答1: you need following permision on the database. [db_datareader] [db_datawriter] [db_ddladmin] For full control over database use [db_owner] 回答2: Clearly it depends on what your migrations are/

问题 How can I get all elements that are in another list by ID? For eg; I have List roles; I'd like to get all roles from the database that are in this this list by their Id. I'm using code-first. I did this and it threw an error: var roles = db.Roles.Where(r => user.Roles.Any(ur => ur.RoleId == r.RoleId)); RoleId is of type int. Error: Unable to create a constant value of type 'SampleMVC.Domain.Role'. Only primitive types ('such as Int32, String, and Guid') are supported in this context. 回答1: var

问题 This is my code, very simple... var newUser = new User(); newUser.Id=id; newUser.Email = email; this.DataContext.Set<User>().Add(newUser); this.DataContext.SaveChanges(); The error I get is a sqlexception at this.DataContext.SaveChanges(); stating that: Cannot insert the value NULL into column 'Id', table 'xxxxx.dbo.Users'; column does not allow nulls. INSERT fails. I have debugged and found that there is value in Id & Email in newUser at this.DataContext.Set<User>().Add(newUser); If this is

问题 I've updated to EF6 and it hasn't been fun. I have created a new migration that is just changing two fields to nullable. public partial class AllowNullableFieldsForImage : DbMigration { public override void Up() { AlterColumn("dbo.Scabs", "image_height", c => c.Int()); AlterColumn("dbo.Scabs", "image_width", c => c.Int()); } public override void Down() { AlterColumn("dbo.Scabs", "image_width", c => c.Int(nullable: false)); AlterColumn("dbo.Scabs", "image_height", c => c.Int(nullable: false));

问题 In my model i have some entities decorated with StringLength attribute: [StringLength(128)] public string FirstName { get; set; } Also i have disable unicode for all string properties this way: protected override void OnModelCreating(DbModelBuilder modelBuilder) { base.OnModelCreating(modelBuilder); modelBuilder.Properties<string>().Configure(p => p.IsUnicode(false)); } The problem is that all string properties decorated with the mentioned attribute are ignoring this setting when generating

问题 In my model i have some entities decorated with StringLength attribute: [StringLength(128)] public string FirstName { get; set; } Also i have disable unicode for all string properties this way: protected override void OnModelCreating(DbModelBuilder modelBuilder) { base.OnModelCreating(modelBuilder); modelBuilder.Properties<string>().Configure(p => p.IsUnicode(false)); } The problem is that all string properties decorated with the mentioned attribute are ignoring this setting when generating

问题 I encounter exception error below when i try to add a new entry in the database with : db.patient_visit.Add(pv); db.SaveChanges(); An exception of type 'System.InvalidOperationException' occurred in project.dll but was not handled in user code Additional information: project.Models.tableName:The field pvid must be a string or array type with a maximum length of '20'. Before this, my model is automatically and originally set like below because i did Code-First migration with existing database.

问题 I am having this strange behavior all of a sudden (i have compared my files in version control (tfs) to be sure i did not change anything and i didn't found anything different). I am seeding my database with some metadata and i see that it has a very strange behavior i never saw before. I am inserting a Entity "Product" and it inserts this entity 2 times , first insert is correct and has everything it should have, the other one has NULL properties (string values) but some (like datetimes)

问题 I'm using the new EF code first to one project of mine, and i'm getting a weird error, my mode is: abstract class Member { public virtual int MemberId; ... some other stuff } class User : Member { public virtual string Name; ... some more props no new key defined } class MyDbContext { public DbSet<User> Users {get;set;} } The result of the deployment to SQL Server is just ok, i've a Members Table and a Users Table (TPC). Now in my main i've the following code: static Main() { User x,y; using

问题 I've just started a new company who are happy for me to use CodeFirst - but want the database fields camel cased. I'm currently writing a lot of this kind of stuff ... [Column("active")] public bool Active { get; set; } [Column("paymentType")] public string PaymentType { get; set; } Is there any way I can just set it all to Camel Case the database, rather than having to decorate all my properties? Thanks 回答1: You can use code first custom conventions If using Fluent Api, you could