带有dotnet核心的REST API

Question

感谢您的观察，我确实将它们应用了以下代码，但在测试api之后未返回任何数据。我什至用我的连接字符串代替dbcontext还是一无所有！当阅读器关闭且阅读器处于打开状态时，我收到此错误无效的调用FieldCount的尝试。我在这种情况下已有一周的时间了，任何帮助。FromSql查询仅返回单个表的实体。我的存储过程带有一个参数，并具有4个表的联接。我已经尝试使用“ ExecuteSqlCommand”查询，因为结果是-1。using System.Threading.Tasks;using Microsoft.AspNetCore.Mvc;using ActivaMobileAgent.Persistence;using Microsoft.EntityFrameworkCore;using ActivaMobileAgent.Model;using System.Linq;using System.Collections.Generic;using System.Data.SqlClient;using System;using Dapper;using System.Data;using System.Data.Common; namespace ActivaMobileAgent.Controllers{    [Route("/api/Policy")]    public class PolicyController : Controller    {    private readonly ActivaMobileAgentDbContext context;    public PolicyController(ActivaMobileAgentDbContext context) => this.context = context;    public readonly string connectionString = "Data Source=Localhost;Initial Catalog=HELLOxx;User=sa; Password=Helloxx";    [HttpGet("{id}")]    public async Task<IActionResult> GetPolicy(string id)    {        using (var connection = new SqlConnection("Data Source=Localhost;Initial Catalog=Helios;User=sa; Password=P@ssw0rd"))        {            SqlCommand command = new SqlCommand();            command.Connection = connection;            command.CommandType = System.Data.CommandType.StoredProcedure;            command.CommandText ="dbo.sproc_Contract_Get";            command.Parameters.Add(new SqlParameter("@ContractNumber", SqlDbType.VarChar) { Value = id });            connection.Open();            using (var result = await command.ExecuteReaderAsync())            {                return Json(result);            }        }    }}}