新建数据库

create database mockstu

新建web项目

安装Microsoft.EntityFrameworkCore.SqlServer包

设置连接字符串

新建model

using MockStuWeb.Models.EnumTypes;
using System.ComponentModel.DataAnnotations;

namespace MockStuWeb.Models
{
    /// <summary>
    /// 学生类
    /// </summary>
    public class Student
    {
        /// <summary>
        /// 唯一标识
        /// </summary>
        public int Id { get; set; }

        /// <summary>
        /// 姓名
        /// </summary>
        [Display(Name = "名字")]
        [Required(ErrorMessage = "请输入名字"), MaxLength(50, ErrorMessage = "名字的长度不能超过50个字符")]
        public string? Name { get; set; }

        /// <summary>
        /// 主修课程
        /// </summary>
        [Required(ErrorMessage ="请选择主修课程")]
        [Display(Name = "主修课程")]
        public MajorEnum? Major { get; set; }

        /// <summary>
        /// 邮箱
        /// </summary>
        [Display(Name = "邮箱")]
        [RegularExpression(@"^[a-zA-Z0-9_.+-]+@[a-zA-Z0-9-]+\.[a-zA-Z0-9-.]+$", ErrorMessage = "邮箱的格式不正确")]
        [Required(ErrorMessage = "请输入邮箱地址,它不能为空")]
        public string? Email { get; set; }
    }
}

新建dbContenxt

using Microsoft.EntityFrameworkCore;
using MockStuWeb.Models;

namespace MockStuWeb.Infrastructure;

public class AppDbContext:DbContext
{
    /// <summary>
    /// 构造函数注入
    /// </summary>
    /// <param name="options"></param>
    public AppDbContext(DbContextOptions<AppDbContext> options):base(options)
    {
    }
    
    public DbSet<Student> Students{get;set;}

}

program.cs中使用

builder.Services.AddDbContextPool<AppDbContext>(options =>
{
    options.UseSqlServer(configuration.GetConnectionString("MockStudentDBConnection"));
});

安装dotnet-ef

dotnet tool install --global dotnet-ef

创建迁移

cd .\MockStuWeb\
dotnet ef migrations add InitialCreate --namespace .\MockStuWeb.csproj --output-dir Migrations

安装Microsoft.EntityFrameworkCore.Tools，顺便升级一下sql server包


需要改代码

更新到数据库中

dotnet ef database update InitialCreate

启用种子数据

Infrastructure下新建ModelBuilderExtensions

using Microsoft.EntityFrameworkCore;
using MockStuWeb.Models;
using MockStuWeb.Models.EnumTypes;

namespace MockStuWeb.Infrastructure;

public static class ModelBuilderExtensions
{
    public static void Seed(this ModelBuilder modelBuilder)
    {
        modelBuilder.Entity<Student>().HasData(
            new Student
            {
                Id = 2,
                Name = "张三",
                Major = MajorEnum.ComputerScience,
                Email = "zhangsan@52abp.com"
            }
        );
    }
}

AppDbContext添加如下代码

/// <summary>
/// 模型创建的时候
/// </summary>
/// <param name="modelBuilder"></param>
protected override void OnModelCreating(ModelBuilder modelBuilder)
{
    modelBuilder.Seed();
}

添加迁移记录并更新

dotnet ef migrations add AlterStudentsSeedData --namespace .\MockStuWeb.csproj --output-dir Migrations
dotnet ef database update AlterStudentsSeedData

进行回退

dotnet ef migrations list
dotnet ef migrations remove -f

只能手动修改一下代码
建立表格的代码注释掉


单条数据也可以这么写

进行回退

dotnet ef migrations list
dotnet ef migrations remove -f
dotnet ef database update InitialCreate

把这次迁移的文件删除即可

参考