英文:
Data is not being written to SQL database
问题
我正在尝试使用 ASP.NET Core 6 构建具有数据持久性的实时聊天应用程序。
我的问题是：我配置了 SignalR 并且它正常工作（在 UI 上进行更改）。然而，它不会更新数据库（我使用 Entity Framework Core 以代码优先的方式）。
我的应用程序 DbContext：
using Microsoft.EntityFrameworkCore;
using VGChat_demo.Models;
namespace VGChat_demo.Data
{
public class ApplicationDbContext : DbContext
{
public ApplicationDbContext(DbContextOptions<ApplicationDbContext> options) : base(options)
{
}
public DbSet<Message> Messages { get; set; }
}
}
我的聊天 Hub：
using Microsoft.AspNetCore.SignalR;
using VGChat_demo.Data;
using VGChat_demo.Models;
namespace VGChat_demo.Hubs
{
public class ChatHub : Hub
{
private readonly ApplicationDbContext _dbContext;
public ChatHub(ApplicationDbContext dbContext)
{
_dbContext = dbContext;
}
public async Task SendMessage(string user, string content)
{
var message = new Message
{
User = user,
Content = content,
Timestamp = DateTime.UtcNow
};
_dbContext.Messages.Add(message);
await Clients.All.SendAsync("ReceiveMessage", message.User, message.Content, message.Timestamp);
await _dbContext.SaveChangesAsync();
}
}
}
我在以下位置设置了断点：
await _dbContext.SaveChangesAsync();
程序运行到该行，但不会将任何内容保存到我的数据库（迁移成功，我得到了与我的消息模型同名的数据库）。
英文:
I am trying to build real time chat app with data persistence using ASP.NET Core 6.
My problem is: I configured SignalR and it works properly (it makes changes on UI). However, it does not update the database (I am using Entity Framework Core with a code-first approach).
My application DbContext:
using Microsoft.EntityFrameworkCore;
using VGChat_demo.Models;
namespace VGChat_demo.Data
{
public class ApplicationDbContext : DbContext
{
public ApplicationDbContext(DbContextOptions<ApplicationDbContext> options) : base(options)
{
}
public DbSet<Message> Messages { get; set; }
}
}
My chat hub:
using Microsoft.AspNetCore.SignalR;
using VGChat_demo.Data;
using VGChat_demo.Models;
namespace VGChat_demo.Hubs
{
public class ChatHub : Hub
{
private readonly ApplicationDbContext _dbContext;
public ChatHub(ApplicationDbContext dbContext)
{
_dbContext = dbContext;
}
public async Task SendMessage(string user, string content)
{
var message = new Message
{
User = user,
Content = content,
Timestamp = DateTime.UtcNow
};
_dbContext.Messages.Add(message);
await Clients.All.SendAsync("ReceiveMessage", message.User, message.Content, message.Timestamp);
await _dbContext.SaveChangesAsync();
}
}
}
I put a breakpoint on
await _dbContext.SaveChangesAsync();
Program runs to that line, but it does not save anything to my database (migration is successful, I get the database named same with my message model)
答案1
得分: 1
我解决了。
显然是我在迁移后更改了字段名称。
迁移文件无法找到模型上对应的字段。
英文:
I solved it.
It's appearently I changed field names after migration.
Migration file could not find corresponding fields on model.
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