獲取錯誤作為@Parameter1 不是過程的參數

Question

我正在從這個視頻中學習 mvc，我從表單中獲取數據並將其保存到數據庫中。 當我第一次運行我的代碼時，它給出了一個錯誤說明

過程或 function 'spAddEmployee' 需要參數 '@Employee_Name'，但未提供。

我遵循了一個解決方案，其中我將存儲過程初始化為 NULL 但現在我收到另一個錯誤，指出“@Parameter1 不是過程的參數”。

這是我的存儲過程

ALTER PROCEDURE [dbo].[spAddEmployee]
(
    @Employee_Name varchar(max) = NULL,
    @Employee_Age int = NULL,
    @Employee_Salary int = NULL,
    @Employee_City varchar(50) = NULL
)
AS
BEGIN
    INSERT INTO tblEmployee (Employee_Name, Employee_Age, Employee_Salary,  Employee_City)
    VALUES (@Employee_Name, @Employee_Age, @Employee_Salary, @Employee_City)
END

這是我的 ADO.NET 代碼：

public void AddEmployee(Employee employee)
{
    string connectionString = ConfigurationManager.ConnectionStrings["EmployeeContext"].ConnectionString;

    using (SqlConnection con = new SqlConnection(connectionString))
    {
        SqlCommand cmd = new SqlCommand("spAddEmployee", con)
        {
            CommandType = CommandType.StoredProcedure
        };

        SqlParameter paramName = new SqlParameter();
        paramName.ParameterName = "@Employee_Name";
        paramName.Value = employee.Employee_Name;
        cmd.Parameters.Add(paramName);

        SqlParameter paramAge = new SqlParameter();
        paramAge.ParameterName = "@Employee_Age";
        paramAge.Value = employee.Employee_Age;
        cmd.Parameters.Add(paramAge);

        SqlParameter paramSalary = new SqlParameter();
        paramSalary.ParameterName = "@Employee_Salary";
        paramSalary.Value = employee.Employee_Salary;
        cmd.Parameters.Add(paramSalary);

        SqlParameter paramCity = new SqlParameter();
        paramCity.ParameterName = "@Employee_City";
        paramCity.Value = employee.Employee_City;
        cmd.Parameters.Add(paramCity);

        con.Open();
        cmd.ExecuteNonQuery();
    }
}

這是我的 controller 代碼

[HttpPost]
[ActionName("Create")]
public ActionResult Create_Post(FormCollection formCollection)
{
    Employee employee = new Employee();
    employee.Employee_Name = formCollection["Employee_Name"];
    employee.Employee_Age = Convert.ToInt32(formCollection["Employee_Age"]);
    employee.Employee_Salary = Convert.ToInt32(formCollection["Employee_Salary"]);
    employee.Employee_City = formCollection["Employee_City"];
    
    EmployeeBuissnessLayer employeeBuissnessLayer = new EmployeeBuissnessLayer();
    employeeBuissnessLayer.AddEmployee(employee);
    return RedirectToAction("Index");
}

我在線上遇到錯誤

employeeBuissnessLayer.AddEmployee(employee);

請幫助我嘗試了很多解決方案，但都沒有奏效。

Answer 1

這個

    SqlParameter paramName = new SqlParameter();
    paramName.ParameterName = "@Employee_Name";
    paramName.Value = employee.Employee_Name;
    cmd.Parameters.Add(paramName);

應該

    SqlParameter paramName = new SqlParameter();
    paramName.ParameterName = "@Employee_Name";
    // Always set the datatype
    paramName.SqlDbType = SqlDbType.NVarChar;
    // For strings, always set the length
    paramName.Size = 128; // Max string length
    // Ensure you pass DBNull not C# null
    paramName.Value = employee.Employee_Name ?? System.DBNull.Value;
    cmd.Parameters.Add(paramName);

注意：最好不要使用sp前綴命名您的存儲過程。