从对象类型System.RuntimeType到已知的托管提供程序本机类型不存在映射

Question

我有一个带签名的存储过程

PROCEDURE [dbo].[spValidateID]
    @ScanCode       VARCHAR(50),
    @Name           VARCHAR(50) = NULL OUTPUT,
    @ScanTime       DATETIME = NULL OUTPUT,
    @ValidationCode INT = 0 OUTPUT

这应该返回validationCode并填充名称和scanTime变量.我需要在调用时给它scanCode值.

在我的C#代码中,我这样做.

using (var context = new DBEntities())
{
    var pScanCode = new SqlParameter("ScanCode", scanCode);
    var opName = new SqlParameter("Name", name);
    var opScanTime = new SqlParameter("ScanTime", scanTime);
    var opValidationCode = new SqlParameter("ValidationCode", validationCode);

    var test = context.ExecuteStoreQuery<int>("spValidateID @ScanCode, @Name, @ScanTime, @ValidationCode", pScanCode, opName, opScanTime, opValidationCode);
}

但是在运行时遇到错误从对象类型System.RuntimeType到已知的托管提供程序本机类型不存在映射.

任何的想法？？

Answer 1

您缺少sqlparameters和@的输出设置.您的代码应如下所示:

SqlParameter pScanCode = new SqlParameter("@ScanCode", ScanCode);
SqlParameter opName = new SqlParameter("@Name", name);
opName.Direction = System.Data.ParameterDirection.Output;   //Important!
SqlParameter opScanTime = new SqlParameter("@ScanTime", scanTime);
opScanTime.Direction = System.Data.ParameterDirection.Output;   //Important!
SqlParameter opValidationCode = new SqlParameter("@ValidationCode ", validationCode);
opValidationCode.Direction = System.Data.ParameterDirection.Output;   //Important!