Since the System.Data.OracleClient library has been deprecated, we are in the process of migrating our code base to use Oracle Data Provider for .NET (ODP.NET) instead. One
I had the same problem with SqlDataSource Update commands after porting ASPX code to Oracle.DataAcees.Client and solved it by changing OracleCommand.BindByName property in SqlDataSource OnUpdating handler like this:
protected void SqlDataSource_Updating(object sender, SqlDataSourceCommandEventArgs e)
{
Oracle.DataAccess.Client.OracleCommand b_OracleCommand =
(Oracle.DataAccess.Client.OracleCommand)e.Command;
b_OracleCommand.BindByName = true;
}