使用SQL Server而不使用实体框架的ASP.NET Web还原API？ [英] An ASP.NET web restore API with SQL server without using entity framework?

问题描述

How to create an ASP.NET Web Restore API with SQL Server without using entity framework?

I'm having trouble finding a tutorial to create an API Rest ASP.NET Web with SQL Server without entity framework, can someone help me? =( 

我尝试过：



连接：

What I have tried:

conection:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Data.SqlClient;
using Teste.Controllers;

namespace Teste.Models
{
    public class Conexaocs : IDisposable
    {
        private SqlConnection connection;

        public void ConectaBD()
        {
            string stringConexao = "Data Source=localhost;Initial Catalog=Teste;Integrated Security=true";
            connection = new SqlConnection(stringConexao);
            connection.Open();
        }
        public void Dispose()
        {
            //connection.Close();
        }
        public void InserirMarca(Marca marca)
        {
        }
        public List<Marca> consultaMarcas()
        {
            List<Marca> marcas = new List<Marca>();

            SqlCommand query = new SqlCommand();
            query.Connection = connection;
            query.CommandText = "@SELECT * FROM Marca";

            SqlDataReader leitura = query.ExecuteReader();

            while (leitura.Read())
            {
                Marca marca = new Marca();
                marca.MarcaId = (int)leitura["MarcaId"];
                marca.Nome = (string)leitura["Nome"];

                marcas.Add(marca);
            }
            return marcas;
        }
    }
}

和控制器

and controller

sing System;
using System.Collections.Generic;
using System.Data.SqlClient;
using System.Linq;
using System.Net;
using System.Net.Http;
using System.Web.Http;
using Teste.Models;



namespace Teste.Controllers
{
    public class MarcaController : ApiController
    {
        Conexaocs conexao = new Conexaocs();
        private static List<Marca> marcas = new List<Marca>();

        public List<Marca> Get()
        {
            try
            {
                using (conexao = new Conexaocs())
                {
                    marcas = conexao.consultaMarcas();
                    return marcas;
                }
            }
            catch (SqlException e)
            {
                
                return marcas;
            }
        }
}

和错误：

< br $>

and error:

{
    "Message": "Ocorreu um erro.",
    "ExceptionMessage": "ExecuteReader: propriedade Connection não foi inicializada.",
    "ExceptionType": "System.InvalidOperationException",
    "StackTrace": "   em System.Data.SqlClient.SqlCommand.ValidateCommand(String method, Boolean async)\r\n   em System.Data.SqlClient.SqlCommand.RunExecuteReader(CommandBehavior cmdBehavior, RunBehavior runBehavior, Boolean returnStream, String method, TaskCompletionSource`1 completion, Int32 timeout, Task& task, Boolean& usedCache, Boolean asyncWrite, Boolean inRetry)\r\n   em System.Data.SqlClient.SqlCommand.RunExecuteReader(CommandBehavior cmdBehavior, RunBehavior runBehavior, Boolean returnStream, String method)\r\n   em System.Data.SqlClient.SqlCommand.ExecuteReader(CommandBehavior behavior, String method)\r\n   em System.Data.SqlClient.SqlCommand.ExecuteReader()\r\n   em Teste.Models.Conexaocs.consultaMarcas() na D:\\C#\\Teste\\Teste\\Models\\Conexaocs.cs:linha 35\r\n   em Teste.Controllers.MarcaController.Get() na D:\\C#\\Teste\\Teste\\Controllers\\MarcaController.cs:linha 25\r\n   em lambda_method(Closure , Object , Object[] )\r\n   em System.Web.Http.Controllers.ReflectedHttpActionDescriptor.ActionExecutor.<>c__DisplayClass6_1.<GetExecutor>b__3(Object instance, Object[] methodParameters)\r\n   em System.Web.Http.Controllers.ReflectedHttpActionDescriptor.ActionExecutor.Execute(Object instance, Object[] arguments)\r\n   em System.Web.Http.Controllers.ReflectedHttpActionDescriptor.ExecuteAsync(HttpControllerContext controllerContext, IDictionary`2 arguments, CancellationToken cancellationToken)\r\n--- Fim do rastreamento de pilha do local anterior onde a exceção foi gerada ---\r\n   em System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)\r\n   em System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)\r\n   em System.Web.Http.Controllers.ApiControllerActionInvoker.<InvokeActionAsyncCore>d__1.MoveNext()\r\n--- Fim do rastreamento de pilha do local anterior onde a exceção foi gerada ---\r\n   em System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)\r\n   em System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)\r\n   em System.Web.Http.Controllers.ActionFilterResult.<ExecuteAsync>d__5.MoveNext()\r\n--- Fim do rastreamento de pilha do local anterior onde a exceção foi gerada ---\r\n   em System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)\r\n   em System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)\r\n   em System.Web.Http.Dispatcher.HttpControllerDispatcher.<SendAsync>d__15.MoveNext()"
}

推荐答案

虽然您的班级确定了连接，但 consultaMarcas 方法永远不会打开它。



尝试在方法上添加对

While your class does have connection defined, the consultaMarcas method never opens it.

Try adding a call to

ConectaBD()

的调用

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