SqlBulkCopy Insert with Identity Column

I am using the SqlBulkCopy object to insert a couple million generated rows into a database. The only problem is that the table I am inserting to has an identity column. I have tried setting the SqlBulkCopyOptions to SqlBulkCopyOptions.KeepIdentity and setting the identity column to 0's, DbNull.Value and null. None of which have worked. I feel like I am missing something pretty simple, if someone could enlighten me that would be fantastic. Thanks!

edit To clarify, I do not have the identity values set in the DataTable I am importing. I want them to be generated as part of the import.

edit 2 Here is the code I use to create the base SqlBulkCopy object.

SqlBulkCopy sbc = GetBulkCopy(SqlBulkCopyOptions.KeepIdentity);
sbc.DestinationTableName = LOOKUP_TABLE;

private static SqlBulkCopy GetBulkCopy(SqlBulkCopyOptions options = 
    SqlBulkCopyOptions.Default) 
{
    Configuration cfg = WebConfigurationManager.OpenWebConfiguration("/RSWifi");
    string connString =
    cfg.ConnectionStrings.ConnectionStrings["WifiData"].ConnectionString;
    return new SqlBulkCopy(connString, options);
}

To have the destination table assign the identity, DO NOT use the SqlBulkCopyOptions.KeepIdentity option. Instead, don't map the identity from the source, and don't extract it from source to send through to SqlBulkCopy.

Fill the ColumnMapping of the BulkCopy object and don't map the identity column. The identity column will be generated by the target database.

You have two options -

1 - use KeepIdentity and preserve the source's Identity values.

2 - Don't map the Identity field. If you don't try to assign a value the target table will assign one automatically.

This is how I solved it in .NET (dt is your data table):

dt.Columns.Cast<DataColumn>().ForEach((c, i) => sqlBulkCopy.ColumnMappings.Add(c.ColumnName, i + 1));

You basically skip the identity (Id) column by assigning your destination columns with an ordinal starting from 1 instead of 0.

This is the table

CREATE TABLE [dbo].[ProductShippingMethodMap](
	[Id] [int] IDENTITY(1,1) NOT NULL,
	[ProductId] [int] NOT NULL,
	[ShippingMethodId] [int] NOT NULL,
	[ParentProductId] [int] NOT NULL,
 CONSTRAINT [PK_ProductShippingMethodMap] PRIMARY KEY CLUSTERED 
(
	[Id] ASC
)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY]
) ON [PRIMARY]
GO

The bellow C# code is working

 DataTable dtQtyData = new DataTable();
        dtQtyData.Clear();
        dtQtyData.Columns.Add("Id", typeof(int));

    dtQtyData.Columns.Add("ProductId", typeof(int));
    dtQtyData.Columns.Add("ShippingMethodId", typeof(int));
    dtQtyData.Columns.Add("ParentProductId", typeof(int));


    for (int i = 0; i < ShippingMethodIds.Length; i++)
    {
        for (int j = 0; j < ProductIds.Length; j++)
        {
            var productId = ProductIds[j];
            var shippingMethodId = ShippingMethodIds[i];
            dtQtyData.Rows.Add(new object[] {0,productId, shippingMethodId, parentProductId });
        }
       
    }
    var connectionString = new DataSettingsManager().LoadSettings().DataConnectionString;
    SqlBulkCopy bulkcopy = new SqlBulkCopy(connectionString, SqlBulkCopyOptions.Default);
    bulkcopy.DestinationTableName = "ProductShippingMethodMap";
    bulkcopy.WriteToServer(dtQtyData);

Yes, You are right using SqlBulkCopyOptions.KeepIdentity option then bulkcopy writer doesn't think that what is you table structure this object write from start column, so for our need, I am doing in same way to preserve identity field in my table just you have to make a extra column in you datatable object with rest of your needful columns and pass null values to this column then table automatically handles Identity.

When using the JDBC SQLServerBulkCSVFileRecord structures, the identity column DOES need to be mapped, but the value in the identity column is ignored.

In my case it turned out to be blank space inside the column name and in one of the columns I had accidently used hyphon (-) instead of underscore (_) in my SQL table. I replaced blank space and hyphon with underscore in the sql table and it fixed the problem.

Cause :- There were some empty rows in the excel at the end of the data, which possibly looks like blank rows. Bulk upload was trying to upload these blank rows into the table.

Solution :- Select only the rows which contains data - copy the data into the new sheet. Say you have your data in 'Sheet 1', move it to 'Sheet 2' and delete 'Sheet 1'.