Imported excel data showing up as scientific notation

Question

When I am importing data as text from excel, it is importing as scientific notation to SQL, even when I can see at all steps during the process the data appears as text without scientific notation. Here is a snippet of the original file:

Utilizing the ExcelDataReader 3rd party code (https://github.com/ExcelDataReader/ExcelDataReader), I am able to extract a DataTable from the excel file and read it. When reading the data, the column and values show up as I suspect from a scratch console app.

When I run the code responsible for sending to SQL, I can see in the SQL profiler the SQL it is executing. I can copy it and execute it separately, which then imports the data as I would expect. Here is a sample.

declare @p1 dbo.ImportDataTableTest
insert into @p1 values(1623157535)
insert into @p1 values(1690205652)
insert into @p1 values(1690205654)
insert into @p1 values(1623110539)
insert into @p1 values(1623165689)
insert into @p1 values(1623165689)
insert into @p1 values(1623171209)
insert into @p1 values(1623128536)
insert into @p1 values(1623172096)

exec InsertStagingData @ImportDataTable=@p1

My problem shows up here after running the application as normal. This is the result in the table:

InvNo           StagingID
3.22029e+009    6491
3.22028e+009    6492
3.22028e+009    6493
3.22028e+009    6494
3.22029e+009    6495

Here is the scratch app and sql code I am using for this example:

C#

namespace ConsoleApp1
{

    class Program
    {

            static void Main(string[] args)
            {
                string fileName = @"path to the file";

                ExcelDataWrapper wrapper = new ExcelDataWrapper();

                ExcelFile file = wrapper.GetExcelData(fileName);

                DataTable dt = file.ExcelData.Tables[0];

                using (var conn = new SqlConnection("our connection string"))
                using (var command = new SqlCommand("InsertStagingData", conn)
                {
                    CommandType = CommandType.StoredProcedure
                })
                {
                    conn.Open();
                    //This parameter name would be passed in from our steps table and would allow 
                    //for different values to be imported per database
                    command.Parameters.Add(new SqlParameter("@ImportDataTable", dt));
                    command.ExecuteNonQuery();
                }         
            }
    }

}

namespace ExcelDataReaderWrapper
{
    public class ExcelDataWrapper
    {
        public ExcelFile GetExcelData(string pathToFile)
        {

            DataSet ds;

            ds = Read(pathToFile);

            string fileName = Path.GetFileName(pathToFile);

            ExcelFile dataTableWithFileName = new ExcelFile { FileName = fileName, ExcelData = ds };

            return dataTableWithFileName;

        }

        private DataSet Read(string file)
        {
            System.Text.Encoding.RegisterProvider(System.Text.CodePagesEncodingProvider.Instance);
            using (var stream = File.Open(file, FileMode.Open, FileAccess.Read))
            {
                if (file.EndsWith(".xls"))
                {
                    using (IExcelDataReader reader = ExcelReaderFactory.CreateBinaryReader(stream))
                    {
                        var conf = new ExcelDataSetConfiguration
                        {
                            ConfigureDataTable = _ => new ExcelDataTableConfiguration
                            {
                                UseHeaderRow = true
                            }
                        };

                        return reader.AsDataSet(conf);
                    }
                }
                if (file.EndsWith(".xlsx"))
                {
                    using (IExcelDataReader reader = ExcelReaderFactory.CreateOpenXmlReader(stream))
                    {
                        var conf = new ExcelDataSetConfiguration
                        {
                            ConfigureDataTable = _ => new ExcelDataTableConfiguration
                            {
                                UseHeaderRow = true
                            }
                        };

                        return reader.AsDataSet(conf);
                    }
                }
                return null;
            }
        }   
    }
}

SQL:

/****** Object:  UserDefinedTableType [dbo].[ImportDataTableTest]    Script Date: 11/19/2019 12:18:18 PM ******/
CREATE TYPE [dbo].[ImportDataTableTest] AS TABLE(
    [InvNo] [nvarchar](255) NULL
)
GO

CREATE Procedure [dbo].[InsertStagingData]
    @ImportDataTable ImportDataTableTest readonly
AS
BEGIN
    -- SET NOCOUNT ON added to prevent extra result sets from
    -- interfering with SELECT statements.
    SET NOCOUNT ON;

    Insert into StagingPOS([InvNo])
    Select InvNo
    from  @ImportDataTable


END
GO

Is there some solution I am missing that gets the data as I see it from the application and the profiler to the table correctly as a nvarchar field? I tried casting the values, but the import looses some of the precision that I need.

EDIT 1:

I followed the link provided by @pcalkins. This would appear to solve the problem as you can see here:

    ALTER Procedure [dbo].[InsertStagingData]
    @ImportDataTable ImportDataTableTest readonly
AS
BEGIN
    -- SET NOCOUNT ON added to prevent extra result sets from
    -- interfering with SELECT statements.
    SET NOCOUNT ON;

    Insert into StagingPOS([InvNo])
    select  Case When InvNo like '%e+%' or InvNo like '%e-%' then replace(cast(cast(cast([InvNo] as real) as money) as nvarchar(255)),'.00','')
    Else InvNo
    End
    from  @ImportDataTable


END

InvNo       StagingID
3220290048  8435
3220280064  8436
3220280064  8437
3220280064  8438

But when I query the values in my excel file to the results in the table, nothing comes up. The values appear rounded at different points in the number.