我目前正在开发一个应该在 MariaDB 10.4 数据库上工作的 ASP.NET Core Web-API。到目前为止,每当我通过 Visual Studio 2019 启动 IIS 服务器时,都不会引发任何错误或警告。与上述数据库的连接是通过EF核心框架结合Pomelo.Mysl库实现的。相关文件如下所示:
启动.cs:
using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using Microsoft.AspNetCore.Builder;
using Microsoft.AspNetCore.Hosting;
using Microsoft.AspNetCore.HttpsPolicy;
using Microsoft.AspNetCore.Mvc;
using racoon.Data;
using Microsoft.EntityFrameworkCore;
using Microsoft.AspNetCore.Http;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Hosting;
using Microsoft.Extensions.Logging;
using Pomelo.EntityFrameworkCore.MySql;
namespace racoon
{
public class Startup
{
public Startup(IConfiguration configuration)
{
Configuration = configuration;
}
public IConfiguration Configuration { get; }
// This method gets called by the runtime. Use this method to add services to the container.
public void ConfigureServices(IServiceCollection services)
{
services.AddControllers();
services.AddDbContext<CollabradorContext>(options => options.UseMySql("Server=localhost;Database=db;User=usr;Password=foo;"));
}
// This method gets called by the runtime. Use this method to configure the HTTP request pipeline.
public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
{
if (env.IsDevelopment())
{
app.UseDeveloperExceptionPage();
}
app.UseHttpsRedirection();
app.UseRouting();
app.UseAuthorization();
app.UseEndpoints(endpoints =>
{
endpoints.MapControllers();
});
}
}
}
示例上下文.cs:
using Microsoft.EntityFrameworkCore;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using racoon.Models;
using System.Net.Mime;
namespace racoon.Data
{
public class SampleContext : DbContext
{
public SampleContext(DbContextOptions<SampleContext> options) : base(options) {}
public DbSet<Course> Courses { get;set; }
protected override void OnModelCreating(ModelBuilder modelBuilder)
{
modelBuilder.Entity<Course>().ToTable("Course");
}
}
}
using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
namespace racoon.Models
{
public class Course
{
public long Id;
public string Name;
public string Description;
public int Rating;
}
}
DbInitalizer.cs:
using System;
using System.Collections.Generic;
using System.Linq;
using racoon.Models;
using System.Threading.Tasks;
namespace racoon.Data
{
public static class DbInitalizer
{
public static void Initalize(CollabradorContext context)
{
System.Console.WriteLine("Initalize!");
context.Database.EnsureCreated();
if (context.Students.Any())
{
return;
}
var courses = new Course[]
{
new Course{Id=0,Name="Python",Description="Learn the fundamentals of Python",Rating=0},
new Course{Id=1,Name="ML",Description="Learn everything about Machine Learning",Rating=0}
};
foreach (Course c in courses)
{
context.Courses.Add(c);
}
context.SaveChanges();
}
}
}
程序.cs:
using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using Microsoft.AspNetCore.Hosting;
using Microsoft.EntityFrameworkCore.Internal;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Hosting;
using Microsoft.Extensions.Logging;
using racoon.Data;
namespace racoon
{
public class Program
{
public static void Main(string[] args)
{
var host = CreateHostBuilder(args).Build();
host.Run();
}
private static void CreateDbIfNotExists(IHost host)
{
using (var scope = host.Services.CreateScope())
{
var services = scope.ServiceProvider;
try
{
var context = services.GetRequiredService<SampleContext>();
context.Database.EnsureCreated();
}
catch (Exception ex)
{
var logger = services.GetRequiredService<ILogger<Program>>();
logger.LogError(ex, "An error occurred creating the DB.");
}
}
}
public static IHostBuilder CreateHostBuilder(string[] args) =>
Host.CreateDefaultBuilder(args)
.ConfigureWebHostDefaults(webBuilder =>
{
webBuilder.UseStartup<Startup>();
});
}
}