问题
Using the latest pre-release version of EntityFramework 7 (v7.0.0-rc1-final), I have tried to use the Add-Migration PowerShell command through the Package Manager Console in Visual Studio; I have tried to add migrations to my DAL.
With a folder structure that looks something like:
-Project
-DAL
-Context.cs
I have tried variations of the following command:
Add-Migration Initial -OutputDir DAL\Migrations -Context ContextClassName
Including, but not limited to:
Add-Migration Initial -OutputDir DAL\Migrations -Context Project.Namespace.DAL.ContextClassName
Add-Migration Initial -OutputDir DAL\Migrations -Context DAL\Context.cs
To no avail...
The package for the tools is installed like so:
Install-Package Microsoft.EntityFrameworkCore.Tools -Pre
The docs are less than helpful and Get-Help Add-Migration -Examples and -Full, -Detailed etc. give you nothing relating to the expected format of the -Context parameter.
What is the correct format?
回答1:
You're using the wrong EF7 package! As per the announcement, there's no longer an Entity Framework 7 but only EntityFrameworkCore.
As per your linked documentation and specifically following the documentation section for Full DotNet You need to reference Microsoft.EntityFrameworkCore.* and not EntityFramework.* (for EF7)
Following the instructions of above page and issuing:
Add-Migration -OutputDir DAL\Migrations -Context ContextClassName
I have no issue getting the migration sorted.
来源：https://stackoverflow.com/questions/38125595/what-is-the-correct-syntax-to-the-context-parameter-of-ef-7s-add-migration-com