Asp.Net Core 3.1数据已检索但未保存到数据库中 [英] Asp.Net Core 3.1 Data is retrieved but not saved into database

问题描述

我正在创建一个Asp.Net核心Web应用程序.我已成功将数据库连接到我的应用程序.我可以成功运行所有迁移，甚至可以从数据库中检索数据.但是，当我尝试使用DbContext保存数据时，数据未保存在数据库中.这是我的代码

I am creating an Asp.Net core web application. I have successfully connected database to my app. I can run all the migration successfully and even retrieve data from database. But when I try to save data using my DbContext data is not saved in the database. Here is my code

类别模型类

public class Category
{
    public int Id { get; set; }
    public string Name { get; set; }
}

类别控制器

public class CategoryController : Controller
{
    private readonly AppDbContext dbContext;

    public CategoryController(AppDbContext dbContext)
    {
        this.dbContext = dbContext;
    }

    [HttpGet]
    public IActionResult Index()
    {
        var categories = dbContext.Categories.ToList();
        return View(categories);
    }

    [HttpGet]
    public IActionResult Create()
    {
        return View();
    }

    [HttpPost]
    public IActionResult Create(Category category)
    {
        if (ModelState.IsValid)
        {
            dbContext.Categories.Add(category);
            return RedirectToAction(nameof(Index));
        }
        return View();
    }
}

查看

<form asp-action="Create">
        <div asp-validation-summary="ModelOnly" class="text-danger"></div>
        <div class="form-group">
            <label asp-for="Name" class="control-label"></label>
            <input asp-for="Name" class="form-control" />
            <span asp-validation-for="Name" class="text-danger"></span>
        </div>
        <div class="form-group">
            <input type="submit" value="Create" class="btn btn-primary" />
        </div>
 </form>

DbContext类

public class AppDbContext : DbContext
{
    public AppDbContext(DbContextOptions<AppDbContext> options) : base(options)
    {

    }

    public DbSet<Category> Categories { get; set; }
}

最后是我的启动服务配置文件中的 ConfigureServices方法

and finally my ConfigureServices Method in Startup file

public void ConfigureServices(IServiceCollection services)
    {
        services.AddControllersWithViews();

        services.AddDbContext<AppDbContext>(options => options
        .UseLazyLoadingProxies()
        .UseSqlServer(Configuration.GetConnectionString("AppDbContext")));
    }

我已成功通过Index方法成功获取了我已手动存储在数据库中但无法从表单保存的数据.

I successfully get data in the Index method that I have manually stored in database but cannot save from a form.

推荐答案

有必要调用EntityFramework的 SaveChanges()方法来保存数据:

It is necessary to call SaveChanges() method of EntityFramework to save data:

dbContext.Categories.Add(category);
dbContext.SaveChanges();

在创建，更新，删除操作之后，有必要调用 SaveChanges .

It is necessary to call SaveChanges after creating, updating, deleting operations.

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