在应用程序代码与SQL中，带有OUTPUT参数的存储过程始终返回1

Question

In SQL Server Management Studio:

1. Right click the procedure
2. Execute
3. Do not enter value for the OUTPUT parameter
4. Enter value for another string parameter
5. The correct value is returned (ex: 12+)

Calling code:

DECLARE @return_value int,
        @CustomerID bigint

EXEC @return_value = [dbo].[InsertCustomer]
            @CustomerID = @CustomerID OUTPUT,
            @Name = N'CustomerName'

SELECT @CustomerID as N'@CustomerID'
SELECT 'Return Value' = @return_value

In application code:

1. Run the following code
2. The returned value for CustomerID is always 1

Code:

ObjectParameter ob = new ObjectParameter("CustomerID", typeof(long));
var CustomerID = db.InsertCustomer(ob, "CustomerName");

I attempted to change the new ObjectParameter(,) second parameter by passing a type and often object by value (ex: 0, 1 etc) but with no avail.

What could have went wrong here?

Update :

This is how the Entity Framework procedure code look like:

public virtual int InsertCustomer(ObjectParameter customerID, string name)
{
    var nameParameter = name != null ?
            new ObjectParameter("Name", name) :
            new ObjectParameter("Name", typeof(string));

    return ((IObjectContextAdapter)this).ObjectContext.ExecuteFunction("InsertCustomer", customerID, nameParameter);
}

Answer 1

Straight ADO :

Please refer to this link. . You need to specify your output parameter in the proc and you need to specify it in the calling code.

SqlParameter outParam = new SqlParameter("CustomerID", 0);

using (SqlConnection con = new SqlConnection(System.Configuration.ConfigurationManager.ConnectionStrings["StringName"].ConnectionString))
{
    using (SqlCommand cmd = new SqlCommand("InsertCustomer", con))
    {
        cmd.CommandType = CommandType.StoredProcedure;              
        cmd.Parameters.Add("@Name", SqlDbType.VarChar).Value = CustomerName;
                    cmd.Parameters.Add(outParam.ParameterName, SqlDbType.BigInt).Direction = ParameterDirection.Output;                 
        con.Open();

        var CustomerID = Convert.ToInt64(cmd.Parameters["CustomerID"].Value);
    }
}

Entity Framework :

Refer to this link

ObjectParameter ob = new ObjectParameter("CustomerID", 0);

// Wrong
var CustomerID = db.InsertCustomer(ob, "CustomerName");

// Right
db.InsertCustomer(ob, "CustomerName");
var CustomerID = (long)ob.Value;