DbFirst:
Microsoft.EntityFrameworkCore
Microsoft.EntityFrameworkCore.Design
Microsoft.EntityFrameworkCore.SqlServer
Microsoft.EntityFrameworkCore.SqlServer.Design
Microsoft.EntityFrameworkCore.Tools
生成：
Scaffold-DbContext -Connection "Server=.;Database=WriteAspNetCoreDataBase;uid=sa;pwd=sa123" Microsoft.EntityFrameworkCore.SqlServer -OutputDir "Models"
Migration:
context.Database.EnsureDeleted(); //删除数据库
context.Database.EnsureCreated(); //创建数据库和表
add-migration Init02
update-database
dotnet ef migrations add Init07
dotnet ef database update