Net Core + EF Core + Sql Server

1.新建空项目

2.创建实体类库

创建实体

　　

 　

public class ClassInfo
    {
        [DatabaseGenerated(DatabaseGeneratedOption.Identity)]  //设置自增
        public int SeqNum { get; set; }        
        [Key,MaxLength(50)]
        public string ClassID { get; set; }
        //[Required]必填
        [Required, MaxLength(50)]
        public string ClassName { get; set; }
        [MaxLength(255)]
        public string Disc { get; set; }
    }



public class UsersInfo
    {
        [DatabaseGenerated(DatabaseGeneratedOption.Identity)]  //设置自增
        public int SeqNum { get; set; }
        [Key,MaxLength(50)]
        public string UserID { get; set; }
        //[Required]必填
        [Required,MaxLength(50)]
        public string UserName { get; set; }
        [MaxLength(1)]
        public int Gender { get; set; }
        [MaxLength(50)]
        public string BelongClass { get; set; }
        [MaxLength(255)]
        public string Disc { get; set; }
    }

3.再创建一个类库项目

创建DemoContext类（与数据库交互）

　　

　　

public class DemoContext : DbContext
    {
        protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
        {
            optionsBuilder.UseSqlServer(
                connectionString: "server=.;database=MyTestDB;uid=sjz2018dbuser;pwd=1ECD9E*#E9DCE1;"
            );
        }

        public DbSet<ClassInfo> ClassInfos { get; set; }
        public DbSet<UsersInfo> UsersInfos { get; set; }
    }

所引nuget包

4.测试结果

新建一个控制台，测试。

static void Main(string[] args)
        {
            //用完即释放
            using var db = new DemoContext();

            var c = new ClassInfo
            {
                ClassID = "10001",
                ClassName = "三年级一班"
            };
            db.ClassInfos.Add(c);
            var count = db.SaveChanges();

            Console.WriteLine(count);
        }