在实体框架核心。

从migrations文件夹中删除所有文件。 输入控制台 Dotnet ef数据库drop -f -v dotnet ef迁移添加初始化 更新dotnetef数据库 (或用于包管理器控制台) Drop-Database -Force -Verbose Add-Migration初始 - database就

UPD:只有在不关心当前持久化数据时才这样做。如果有，就用Greg Gum的答案

要解决这个问题，你需要:

删除Migrations文件夹中的所有*.cs文件。 删除数据库中的_MigrationHistory表 执行Enable-Migrations -EnableAutomaticMigrations -Force命令 执行Add-Migration Reset命令

然后，在公共部分类Reset: DbMigration类中，你需要注释所有现有的和当前的table:

public override void Up()
{
// CreateTable(
// "dbo.<EXISTING TABLE NAME IN DATABASE>
// ...
// }
...
}

如果你错过了这一点，一切都将失败，你必须重新开始!

现在运行Update-Database -verbose

如果您正确地完成了上述操作，那么这应该是成功的，现在您可以正常进行了。

问题:你搞砸了你的迁移，你想重置它而不删除现有的表。

问题:您不能重置数据库中现有表的迁移，因为EF希望从头创建表。

应对方法:

Delete existing migrations from Migrations_History table. Delete existing migrations from the Migrations Folder. Run add-migration Reset. This will create a migration in your Migration folder that includes creating the tables (but it will not run it so it will not error out.) You now need to create the initial row in the MigrationHistory table so EF has a snapshot of the current state. EF will do this if you apply a migration. However, you can't apply the migration that you just made as the tables already exist in your database. So go into the Migration and comment out all the code inside the "Up" method. Now run update-database. It will apply the Migration (while not actually changing the database) and create a snapshot row in MigrationHistory.

现在您已经重置了迁移，可以继续进行正常的迁移。

在实体框架核心。

从migrations文件夹中删除所有文件。 输入控制台 Dotnet ef数据库drop -f -v dotnet ef迁移添加初始化 更新dotnetef数据库 (或用于包管理器控制台) Drop-Database -Force -Verbose Add-Migration初始 - database就

UPD:只有在不关心当前持久化数据时才这样做。如果有，就用Greg Gum的答案

VSC(Visual Studio Code) - .Net核心

1.删除状态:删除项目中的迁移文件夹;

2.删除数据库中__MigrationHistory的记录;

3.Dotnet ef数据库drop -v then 您确定要删除服务器上的数据库'<your-database' ?(y / N) 写“N”

4.. dotnet ef迁移添加Initial，然后将20211014110429_initial类的代码写入__MigrationHistory的

对于 EFCore 6/7：

为了将所有更改合并到单个文件中，并将其应用到现有数据库中，同时保留所有数据(即在Production和其他开发中)，以下步骤对我来说很有效:

Delete existing migrations from the Migrations Folder in your project. Delete the Context Snapshop files. I.e. ApplicationDbContextSnapshot.cs, DatabaseContextModelSnapshot.cs or similar. Rebuild your solution Run Add-Migration Initial. (Can be named how you like instead of Initial). This will create a migration in your Migration folder that includes creating the tables, but won't be applied yet. Open the generated Migration file and comment out all the code inside the "Up" method, so that it doesn't make any changes to all your existing tables. (This allows us to update the database in the correct format, without making any changes in the next step) Before the commented code within the Up function, add migrationBuilder.Sql("DELETE FROM [dbo].[__EFMigrationsHistory]"); to have the delete/truncate applied during migration

public partial class Initial : Migration
{
    public override void Up()
    {
        migrationBuilder.Sql("DELETE FROM [dbo].[__EFMigrationsHistory]");
        /*
          OTHER COMMENTED OUT CODE
        */
    }

    public override void Down()
    {
    }
}

Run Update-Database. It will apply the Migration and remove existing migration tracking entriers (while not actually changing the database schema) and create a snapshot row in __EFMigrationsHistory Submit this code and apply to your dev, staging and production databases as you normally would (Ensure the code is still commented out in the Up function, no changes will be applied, except a new entry created in __EFMigrationsHistory) Remove migrationBuilder.Sql("DELETE FROM [dbo].[__EFMigrationsHistory]"); and uncomment all the code from step 5 and submit back to source control. (This way new devs can create the db from scratch. If someone forgot to update their existing database, it'll error out and complain that the tables already exist, so they can just comment the Initial file out and apply.)