- by 软件工艺师
- 写model类
![image-20210112211354112](Entity Framework Core 3.1 学习文档.assets/image-20210112211354112.png)
- 安装.netcore sqlserver包 继承dbcontext 作映射
public DbSet<League> Leagues { get; set; }
public DbSet<Club> Clubs { get; set; }
public DbSet<Player> Players { get; set; }
- 重载方法,指定数据库连接字符串
protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
{
optionsBuilder.UseSqlServer(
"data source = .; initial catalog = Entity Framework Core 3.1 LearningDemo; persist security info = True; user id = sa; password = 123456; MultipleActiveResultSets = True; ");
}
![image-20210112211553126](Entity Framework Core 3.1 学习文档.assets/image-20210112211553126.png)
- 安装nuget包,便于生成migration文件
![image-20210112211758503](Entity Framework Core 3.1 学习文档.assets/image-20210112211758503.png)
- 程序包管理器控制台
![image-20210112212857802](Entity Framework Core 3.1 学习文档.assets/image-20210112212857802.png)
修改操作
基于注解
![image-20210112213730700](Entity Framework Core 3.1 学习文档.assets/image-20210112213730700.png)
修改数据库
![image-20210112213916978](Entity Framework Core 3.1 学习文档.assets/image-20210112213916978.png)
![image-20210112214531610](Entity Framework Core 3.1 学习文档.assets/image-20210112214531610.png)
![image-20210411102825239](Entity Framework Core 3.1 学习文档.assets/image-20210411102825239.png)
通过where 的expression委托表达式,传进来这个就好了,这样会方便很多啊
asnotracking这样直接就成游离态了
在seed方法中 添加 addorupdate可以直接往数据库里直接添加测试数据
![image-20210411103502567](Entity Framework Core 3.1 学习文档.assets/image-20210411103502567.png)