使用 Dapper 时无法在 .NET Core Web API 中获取任何结果集

Question

我无法在 .NET Core Web API 项目之一中获取任何输出。 .NET SDK： 版本：7.0.400 提交：73bf45718d 下面是连接到数据库并应该返回结果的服务之一，但即使 SP 工作正常，它也没有给出输出。

using EmployeeUsingDapper.Model;
using Dapper;
using Oracle.ManagedDataAccess.Client;
using Microsoft.Extensions.Configuration;
using System.Data;

namespace EmployeeUsingDapper.Services
{
    public class EmployeeListService : IEmployeeListService
    {
        private readonly IDatabaseService _databaseService;
        private readonly ILogger<EmployeeListService> _logger;

        public EmployeeListService(ILogger<EmployeeListService> logger, IDatabaseService databaseService)
        {
            _databaseService = databaseService;
            _logger = logger;
        }

        public async Task<(IEnumerable<Employee>, CallStatus?) > GetEmployeeList(InputParametersForSearch inputParameters)
        {
            try
            {
                using var connection = _databaseService.GetConnection();
                var parameters = new OracleDynamicParameters();

                //Input Parameters
                parameters.Add("iName", OracleDbType.Char, ParameterDirection.Input, inputParameters.UserName);
                parameters.Add("ino", OracleDbType.Int32, ParameterDirection.Input, inputParameters.no);
                parameters.Add("iPassport", OracleDbType.Char, ParameterDirection.Input, inputParameters.Passport);
                parameters.Add("iID", OracleDbType.Int32, ParameterDirection.Input, inputParameters.LOEID);
                parameters.Add("iLastName", OracleDbType.Char, ParameterDirection.Input, inputParameters.LastName);
                parameters.Add("iFirstName", OracleDbType.Char, ParameterDirection.Input, inputParameters.FirstName); 

                //Output Parameters
                parameters.Add("oCallStatus", oracleDbType: Oracle.ManagedDataAccess.Client.OracleDbType.RefCursor, ParameterDirection.Output);
                parameters.Add("EMPLISTCURSOR", oracleDbType: Oracle.ManagedDataAccess.Client.OracleDbType.RefCursor, ParameterDirection.Output);

                var result = await connection.QueryMultipleAsync("getEmployeeList", parameters, commandType: CommandType.StoredProcedure);

                var emps = await result.ReadAsync<Employee>().ConfigureAwait(false);
                var emplist = emps.ToList();
                var callStatus = await result.ReadFirstOrDefaultAsync<CallStatus>().ConfigureAwait(false);

                //Log the values
                _logger.LogInformation($"emps: {emplist.LongCount()}");
                _logger.LogInformation($"Call status: {callStatus?.Status}, message: {callStatus?.Message}, ErrorID: {callStatus?.ErrorID}");
                
                return (emplist, callStatus);
            }
            catch (Exception ex)
            {
                _logger.LogError(ex, "Error executing stored procedure.");
                return (null, null);
            }
        }
    }
}

下面是Employee类

public class Employee
{
    public int? NOM { get; set; }    
}

下面是我的存储过程。 当我测试这个 SP 时，它工作正常并返回结果，但在 .NEt Core 中它返回 null

PROCEDURE getEmployeeList (iName           IN     VARCHAR2,
                           ino             IN     NUMBER,
                           iPassport       IN     VARCHAR2,
                           iID             IN     NUMBER,
                           iLastName       IN     VARCHAR2,
                           iFirstName      IN     VARCHAR2,
                           oCallStatus        OUT SYS_REFCURSOR,
                           EMPLISTCURSOR      OUT SYS_REFCURSOR)
IS
    vInputParam   VARCHAR2 (4000);
BEGIN
    vInputParam :=
           'iUserName:'
        || iUserName
        || ' ino:'
        || ino
        || ' iPassport:'
        || iPassport
        || ' ID:'
        || iID
        || ' iLastName:'
        || iLastName
        || ' iFirstName:'
        || iFirstName;

    --log input parameters

    OPEN EMPLISTCURSOR FOR SELECT empno     NOM
                             FROM employee
                            WHERE ROWNUM < 10;

    OPEN oCallStatus FOR
        SELECT 'Y' STATUS, NULL MESSAGE, NULL ERROR_ID FROM DUAL;
EXCEPTION
    WHEN OTHERS
    THEN
        gSqlErrorCode := SQLCODE;
        gSqlErrorMessage := SQLERRM;

        OPEN oCallStatus FOR
            SELECT 'N'                                         STATUS,
                   'Error occured while getting employee list'     MESSAGE,
                   REPLACE (gSqlErrorCode, 'ORA', '')          ERROR_ID
              FROM DUAL;

        CLOSE EMPLISTCURSOR;
--log Error
END getEmployeeList;

下面是 OracleDynamicParameters 类

public class OracleDynamicParameters : SqlMapper.IDynamicParameters
{
    private readonly DynamicParameters dynamicParameters = new DynamicParameters();
    private readonly List<OracleParameter> oracleParameters = new List<OracleParameter>();

    public void Add(string name, OracleDbType oracleDbType, ParameterDirection direction, object value = null, int? size = null)
    {
        OracleParameter oracleParameter;
        if (size.HasValue)
        {
            oracleParameter = new OracleParameter(name, oracleDbType, size.Value, value, direction);
        }
        else
        {
            oracleParameter = new OracleParameter(name, oracleDbType, value, direction);
        }

        oracleParameters.Add(oracleParameter);
    }

    public void Add(string name, OracleDbType oracleDbType, ParameterDirection direction)
    {
        var oracleParameter = new OracleParameter(name, oracleDbType, direction);
        oracleParameters.Add(oracleParameter);
    }

    public void AddParameters(IDbCommand command, SqlMapper.Identity identity)
    {
        ((SqlMapper.IDynamicParameters)dynamicParameters).AddParameters(command, identity);

        var oracleCommand = command as OracleCommand;

        if (oracleCommand != null)
        {
            oracleCommand.Parameters.AddRange(oracleParameters.ToArray());
        }
    }

    public T Get<T>(string name)
    {
        return dynamicParameters.Get<T>(name);
    }
}

Answer 1

交换

callStatus

和

emps

的输出参数获取结果的位置。

同时，我不明白使用

await

和

ConfigureAwait(false)

的目的。

var callStatus = await result.ReadFirstOrDefaultAsync<CallStatus>();

var emps = await result.ReadAsync<Employee>();
var emplist = emps.ToList();