ef-migrations

问题 I have a web application that I install on my customers' computers for their inner use. I use C# MVC5 and code-first Entity Framework. I used automatic migration=true but I stopped and set it to false. I installed it on a production environment (release) - with a deploy-package (no Visual Studio). I have a customer with the application - version 1. Now I want to upgrade to version 2. I want to enable to upgrade the App's DB (in production file, with CMD installation from a package), but to

问题 I have a dbcontext class where i have initialized 4 dbsets. My connection string is <connectionStrings> <add name="somename" connectionString="Data Source=.; initial catalog=someDb; user ID=ab; Password:111111; MultipleActiveResultSets=True;" providerName="System.Data.SqlClient" /> </connectionStrings> My dbcotext class is public AstroEntities(): base("somename") { Database.SetInitializer<AstroEntities>(new CreateDatabaseIfNotExists<AstroEntities>()); } protected override void OnModelCreating

问题 I have a active project that has always used C#, Entity Framework, and SQL Server. However, with the feasibility of NoSQL alternatives daily increasing, I am researching all the implications of switching the project to use MongoDB. It is obvious that the major transition hurdles would be due to being "schema-less". A good summary of what that implies for languages like C# is found here in the official MongoDB documentation. Here are the most helpful relevant paragraphs (bold added): Just

问题 I am using Entity Framework with Auto Migrations. So when I add a new model to my Context, my database is updated and new table is created. What I want to do is the opposite, droping the table completely from database. However, removing the definition from Context class does not work. public class CompanyContext : DbContext { public DbSet<Permission> Permissions { get; set; } public DbSet<Company> Companies { get; set; } protected override void OnModelCreating(DbModelBuilder modelBuilder) {

问题 I'm trying to set the foreign key name (not the foreign key column) using Code First Migrations on EF6.4. I know that it can be set by updating the generated migration code, like so: .ForeignKey("Documents", Function(t) t.DocumentId, cascadeDelete:=True, name:="FK_Sections_Documents") ...but I'd like to do it before the migration is added, using the Fluent API. I seem to recall something about the HasForeignKey() call accepting a Func that contains a call to an anonymous type in its body,

问题 I am trying to add a migration (for the first time) to a project using Entity Framework 6.0.2 for SQL Server Compact (code first). The application is having no problems communicating with the database. The migration is failing with the error message: System.InvalidOperationException: No Entity Framework provider found for the ADO.NET provider with invariant name 'System.Data.SqlServerCe.3.5'. Make sure the provider is registered in the 'entityFramework' section of the application config file.

问题 I have a .Net Core WebApplication Project in which the Context Class is in a Class Library. If I hard code the connection string in the OnConfiguring(DbContextOptionsBuilder optionsBuilder) method I can generate migrations. Since it is better to let dependency injection manage the context I would like to add this to the Startup Class. However when I do I get the following error: No database provider has been configured for this DbContext. A provider can be configured by overriding the

问题 How do I get this column as similar to a PERSISTED COMPUTED column in the database? My current attempt (it loads all CompCol rows with null in seed) : public class Call { public Call() { } [Key] public int Id { get; set; } [DatabaseGenerated(DatabaseGeneratedOption.Computed)] public string CompCol { get { return "ABC-" + Convert.ToString(Id).PadLeft(5, '0'); } protected set {} } } 回答1: The solution I found was to : Make sure auto migrations are turned off. This is so that VS will generate a

问题 I struggled to enable my code to run code first EF migrations using different connection strings, and finally got it working. The method I used is outlined in my answer to this question What bothers me is that in order to be able to run the same code using different connection strings I had to 1) Resort to a global setting to store the connection string 2) Introduce a class whose very presence caused the code to behave differently. This is so different to the way I am used to working. Is the

问题 I have inherited a sql server database and an ASP.Net MVC 4 web application which is using Entity Framework 5.0 Code First with Auto Migrations . However, it appears the previous developer forgot to add a Primary Key to one of the tables. I am now trying to do this using Auto Migrations , however, it is not working, no errors either, just seems to be ignoring the command. The table is like this public int CourseDateHistoryID { get; set; } public int CourseDateID { get; set; } public int Event