MVC数据库问题(更新,添加字段)

1.更新模型之后,在"程序包管理控制器"中输入Update-database,就能自动完成更新

2.对于Update-database之后报错:Automatic migration was not applied because it would result in data loss. Set AutomaticMigrationDataLossAllowed to 'true' on your DbMigrationsConfiguration to allow application of automatic migrations even if they might cause data loss. Alternately, use Update-Database with the '-Force' option, or scaffold an explicit migration.（这种方法是试验出来的，不确定好不好使）

方法:依次输入命令

(1):Update-database -force

(2):Update-database -Verbose

(3):Update-database

3.对于输入Update-database,"无法将“Update-base”项识别为 cmdlet、函数、脚本文件或可运行程序的名称。请检查名称的拼写，如果包括路径，请确保路径正确，然后再试一次。"

用 :    Import-Module 项目地址\packages\EntityFramework.6.1.3\tools\EntityFramework.psd1

4、Automatic migration was not applied because it would result in data loss. Set AutomaticMigrationDataLossAllowed to 'true' on your DbMigrationsConfiguration to allow application of automatic migrations even if they might cause data loss. Alternately, use Update-Database with the '-Force' option, or scaffold an explicit migration.（已经确定）

（1）：Add-Migration InitialCreate

（2）：Update-database

5、No migrations configuration type was found in the assembly 'DAL'. (In Visual Studio you can use the Enable-Migrations command from Package Manager Console to add a migrations configuration).（没有迁移配置类型。。。）

（1）：Enable-Migrations（改true）

（2）：Update-database