PetaPoco在ASP.NET Core 2.2中使用注入方式访问数据库

.Net Core中一个特别重要的特性就是依赖注入功能，那么我们在使用PetaPoco的时候是否也可以使用依赖注入特性呢？

回答当然是可以的啦。使用方法（两种注入方式）如下

services.AddScoped<IDatabase>(
    x =>
       {
           var connectionStrnig = Configuration["ConnectionStrings:MySQL:MvcMySQL"];
           var configuration = DatabaseConfiguration.Build().UsingConnectionString(connectionStrnig)
                            .UsingProvider<MariaDbDatabaseProvider>();
           return new PetaPocoMvcDBContext(configuration);
       });

services.AddScoped<IDatabase, PetaPocoMvcDBContext>(
    (x) =>
         {
             var connectionStrnig = Configuration["ConnectionStrings:MySQL:MvcMySQL"];
             var configuration = DatabaseConfiguration.Build().UsingConnectionString(connectionStrnig)
                            .UsingProvider<MariaDbDatabaseProvider>();
             return new PetaPocoMvcDBContext(configuration);
         });

定义的PetaPocoMvcDBContext类：

namespace PetaPocoEfCoreMvc.DBContext
{
    using System.Data.Common;

    using PetaPoco;
    using PetaPoco.Core;

    public class PetaPocoMvcDBContext:Database
    {
        public PetaPocoMvcDBContext(DbConnection connection, IMapper defaultMapper = null)
            : base(connection, defaultMapper)
        {
        }

        public PetaPocoMvcDBContext(string connectionString, string providerName, IMapper defaultMapper = null)
            : base(connectionString, providerName, defaultMapper)
        {
        }

        public PetaPocoMvcDBContext(string connectionString, DbProviderFactory factory, IMapper defaultMapper = null)
            : base(connectionString, factory, defaultMapper)
        {
        }

        public PetaPocoMvcDBContext(string connectionString, IProvider provider, IMapper defaultMapper = null)
            : base(connectionString, provider, defaultMapper)
        {
        }

        public PetaPocoMvcDBContext(IDatabaseBuildConfiguration configuration)
            : base(configuration)
        {
        }
    }
}

appsetting.json中的数据库连接字符串：

"ConnectionStrings": {
    "MySQL": {
      "MvcMySQL": "server=127.0.0.1;port=3306;uid=root;pwd=123456;database=WireCloud;",
      "provider": "MySql.Data.MySqlClient"
    }
  }

添加UserService相关类：

namespace PetaPocoEfCoreMvc.Service
{
    using PetaPocoEfCoreMvc.Models;

    public interface IUserService
    {
        IEnumerable<User> GetAll();
    }
}

namespace PetaPocoEfCoreMvc.Service
{
    using PetaPoco;
    using PetaPocoEfCoreMvc.Models;

    public class UserService:IUserService
    {
        private readonly IDatabase _database;
　　　   //构造函数注入
        public UserService(IDatabase database)
        {
            _database = database;
        }

        public IEnumerable<User> GetAll()
        {
            return _database.Fetch<User>();
        }
    }
}