如何使用带有迁移的 Entity Framework Core 通过 ASP.NET CORE MVC 连接到现有的 Azure SQL 数据库？

Question

我有一个使用带有 SQL 服务器和 SQL 数据库的 Azure App Services 的应用程序，它们连接到我在 asp MVC 上的 Web 应用程序。 我已经使用分布式 Sql Server 缓存作为我数据库上的一个表，到目前为止一切都运行良好并且相互连接。 现在我想做两件事：

• 将实体框架添加到我的应用程序（我已经有了数据库和连接字符串）
• 运行迁移 - 在我发布我的应用程序之后（如果我添加了一个示例新行或新

表，现在我有新版本）我不知道该怎么做，我查了很多指南，找不到答案。 我在这里找到了一篇与我类似的帖子——但使用了天蓝色的功能。 如果有人可以帮助我完成我需要遵循的步骤（就像他们在那篇文章中所做的那样）以获取实体框架和迁移，我将不胜感激。

这是我的代码：

程序.cs-

using Microsoft.Extensions.Azure;
using Azure.Identity;
var builder = WebApplication.CreateBuilder(args);

if(!builder.Environment.IsDevelopment())
    builder.Configuration.AddAzureKeyVault(new Uri(Environment.GetEnvironmentVariable("VaultUri")), new DefaultAzureCredential());

builder.Services.AddControllersWithViews();
builder.Services.AddAzureClients(clientBuilder =>
{
    clientBuilder.AddBlobServiceClient(builder.Configuration["storage:blob"], preferMsi: true);
    clientBuilder.AddQueueServiceClient(builder.Configuration["storage:queue"], preferMsi: true);
});

builder.Services.AddDistributedSqlServerCache(options =>
{
    options.ConnectionString = builder.Configuration.GetConnectionString("db");
    options.SchemaName = "dbo";
    options.TableName = "_Cache";
});

var app = builder.Build();

// Configure the HTTP request pipeline.
if (!app.Environment.IsDevelopment())
{
    app.UseExceptionHandler("/Home/Error");
    // The default HSTS value is 30 days. You may want to change this for production scenarios, see https://aka.ms/aspnetcore-hsts.
    app.UseHsts();

家庭控制器：

namespace WebAppAzure.Controllers
{
    public class HomeController : Controller
    {
        private readonly BlobServiceClient storage;
        private readonly ILogger<HomeController> logger;
        private readonly IDistributedCache cache;

        public HomeController(BlobServiceClient storage, ILogger<HomeController> logger,
            IDistributedCache cache)
        {
            this.storage = storage;
            this.logger = logger;
            this.cache = cache;
        }

        public IActionResult Index()
        {
            var containerClient = storage.GetBlobContainerClient("public");
            var blob = containerClient.GetBlobClient("image.jpeg");
            var model = blob.Uri.ToString();

            return View(model: model);
        }

        public IActionResult Privacy()
        {
            var stringModel = DateTime.Now.ToString();
            cache.SetString("name", stringModel);
            return View(model: $"SET: {stringModel}");
        }

        public IActionResult About()
        {
            var stringModel = cache.GetString("name");
            return View(model: $"GET: {stringModel}");
        }


        [ResponseCache(Duration = 0, Location = ResponseCacheLocation.None, NoStore = true)]
        public IActionResult Error()
        {
            return View(new ErrorViewModel { RequestId = Activity.Current?.Id ?? HttpContext.TraceIdentifier });
        }
    }
}

Answer 1

• 将实体框架添加到我的应用程序（我已经有了数据库和连接字符串）

使用以下代码添加实体框架并上传到 azure app 服务并运行迁移命令来迁移数据库。

项目中的 DBcontext 文件。

using Microsoft.EntityFrameworkCore;
using WebApplication_72783922.Entity;

namespace WebApplication_72783922
{
    public class DbConnectionEntity : DbContext
    {
        public DbConnectionEntity()
        {

        }
        //string connectionString = Environment.GetEnvironmentVariable("ConnectionStrings:dbcon").ToString();
        public DbConnectionEntity(DbContextOptions<DbConnectionEntity> options) 
            : base(options)
        {

        }
        public virtual DbSet<Users> users { get; set; }
        public virtual DbSet<department> Departments { get; set; }

        protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
        {
            if (!optionsBuilder.IsConfigured)
            {
                optionsBuilder.UseSqlServer("Server=xxxx;Initial Catalog=database;Persist Security Info=False;User ID=adminserver72783922;Password=xxxx;MultipleActiveResultSets=False;Encrypt=True;TrustServerCertificate=False;Connection Timeout=30;");
            }
        }

        protected override void OnModelCreating(ModelBuilder modelBuilder)
        {
            base.OnModelCreating(modelBuilder);
        }
    }
}

Program.cs 文件代码。

using Microsoft.Extensions.Azure;
using Azure.Identity;
using Microsoft.Extensions.Configuration;

var builder = WebApplication.CreateBuilder(args);

if (!builder.Environment.IsDevelopment())
     
// Add services to the container.
builder.Services.AddControllersWithViews();

builder.Services.AddDistributedSqlServerCache(options =>
{
    options.ConnectionString = "Server=xxxx;Initial Catalog=database;Persist Security Info=False;User ID=adminserver72783922;Password=xxxx;MultipleActiveResultSets=False;Encrypt=True;TrustServerCertificate=False;Connection Timeout=30;";
    options.SchemaName = "dbo";
    options.TableName = "_Cache";
});

var app = builder.Build();

// Configure the HTTP request pipeline.
if (!app.Environment.IsDevelopment())
{
    app.UseExceptionHandler("/Home/Error");
    // The default HSTS value is 30 days. You may want to change this for production scenarios, see https://aka.ms/aspnetcore-hsts.
    app.UseHsts();
}

app.UseHttpsRedirection();
app.UseStaticFiles();

app.UseRouting();

app.UseAuthorization();

app.MapControllerRoute(
    name: "default",
    pattern: "{controller=Home}/{action=Index}/{id?}");

app.Run();

• 运行迁移——在我发布我的应用程序之后

Enable Migration using this command on Package Manager Console enable-migrations
Then add-migration InitialCreate
Then create migrationadd-migration test-v1
update database update-database -verbose