Code First开发方式

Posted 2020-10-04 15037075275z

Code First又称代码优先，EF提供类型结构生成SQL并创建数据库中的表

student类

public class student:DbContext 注：DbContext表示一个工作单元和存储库的组合模式,可以用来从数据库查询和组一起变化。
{
public student()
{
Database.SetInitializer(new MigrateDatabaseToLatestVersion<student, DbConfiguration>()); 注：初始化自动迁移
}
public DbSet<message> message { get; set; } 注：默认生成的表的类型为复数形式
}
public class DbConfiguration : DbMigrationsConfiguration<student>
{
public DbConfiguration()
{
AutomaticMigrationsEnabled = true; 注：开启自动迁移
AutomaticMigrationDataLossAllowed = true; 注：迁移的时候是否允许数据丢失
}
}

 

message类

public class message
{
public int messageID 注：当类名加ID时自动设为主键
{
get;
set;
}
public string stuName
{
get;
set;
}
public string stuSex
{
get;
set;
}
public int stuAge
{
get;
set;
}
public long stuPhone
{
get;
set;
}
}

调用 注：如果你写完不调用就不会创建数据库

student stu = new student();    

public ActionResult Index()
{
if (stu.message.Count() == 0) 注：当stu.message.Count()的数据等于零的时候就向stu.message添加数据
{
stu.message.Add(new message() { stuAge = 10, stuName = "张三", stuSex = "男", stuPhone = 12345678912 });
stu.message.Add(new message() { stuAge = 11, stuName = "李四", stuSex = "女", stuPhone = 12145128912 });
stu.message.Add(new message() { stuAge = 12, stuName = "王五", stuSex = "女", stuPhone = 12345742912 });
stu.message.Add(new message() { stuAge = 13, stuName = "赵六", stuSex = "男", stuPhone = 12445678912 });
stu.SaveChanges();
}

}