在 EF Core 中，您还不能从原始 SQL 查询中返回即席类型(他们正在解决这个问题)，因此您需要一个解决方法问题.将此类添加到您的项目中:

In EF Core you can't return ad-hoc types from raw SQL queries yet (they are working on this), so you will need a workaround for this issue. Add this class to your project:

using Microsoft.EntityFrameworkCore;
using Microsoft.EntityFrameworkCore.Infrastructure;
using Microsoft.EntityFrameworkCore.Internal;
using Microsoft.EntityFrameworkCore.Storage;
using Microsoft.Extensions.DependencyInjection;
using System;
using System.Collections.Generic;
using System.Data.Common;
using System.Linq;
using System.Reflection;
using System.Threading;
using System.Threading.Tasks;

namespace Microsoft.EntityFrameworkCore
{

    public static class RDFacadeExtensions
    {
        public static RelationalDataReader ExecuteSqlQuery(this DatabaseFacade databaseFacade, string sql, params object[] parameters)
        {
            var concurrencyDetector = databaseFacade.GetService<IConcurrencyDetector>();

            using (concurrencyDetector.EnterCriticalSection())
            {
                var rawSqlCommand = databaseFacade
                    .GetService<IRawSqlCommandBuilder>()
                    .Build(sql, parameters);

                return rawSqlCommand
                    .RelationalCommand
                    .ExecuteReader(
                        databaseFacade.GetService<IRelationalConnection>(),
                        parameterValues: rawSqlCommand.ParameterValues);
            }
        }
    }
}

然后您可以调用下面的方法并从您的 SP 获取 OUTPUT，这是一个示例:

Then you can call the method below and get the OUTPUT from you SP, here's a sample:

            var _sMsg = new SqlParameter("sMsg", "")
            {
                Direction = ParameterDirection.Output,
                DbType = DbType.String,
                Size = 500
            };

            var sql = "exec sp_foo @sUserId, @sMsg OUTPUT";

            using (var dr = _ctx.Database.ExecuteSqlQuery(sql, _sUserID, _sMsg))
            {
                //here you can retrive your table
                while (dr.DbDataReader.Read())
                {
                    var bar = dr.DbDataReader[0].ToString();
                }

                //here is your OUTPUT
                return _sMsg.Value.ToString();
            }