Day2:DbContext学习

一、创建实体

namespace ConsoleApp1
{
    public class Student
    {
        /// <summary>
        /// 学生ID
        /// </summary>
        public int StudentId { get; set; }
        /// <summary>
        /// 学生姓名
        /// </summary>
        public string? StudentName { get; set; }
        /// <summary>
        /// 性别
        /// </summary>
        public string? Sex { get; set;}
        /// <summary>
        /// 年龄
        /// </summary>
        public int Age { get; set; }
        public Grade? Grade { get; set;}
    }
}

二、定义DbContext派生类

namespace ConsoleApp1
{
    public class EFDbContext:DbContext
    {
        public EFDbContext() :base()
        {
        }

        public DbSet<Student> Students { get; set; }

        public DbSet<Grade> Grades { get; set; }
    }
}

三、生存期

namespace ConsoleApp1 
{
    class Program
    {
        static void Main(string[] args)
        {
            using (var db = new EFDbContext())
            {
                Student stuModel = new Student()
                {
                    StudentName = "Test",
                    Age = 1,
                };
                db.Entry(stuModel).State = EntityState.Added;
                db.SaveChanges();
            }
            Console.WriteLine("success");
            Console.ReadKey();
        }

    }
}

四、配置文件

在app.config配置文件中添加需要连接的服务器名称、数据库的名称和登录密码。