How to check previous record in ADO.NET 2.0 - C# + ASP.NET 2.0

HI

I have a method that reads data from SQL Server and writes into Oracel Table. All working fine.

SQL Server Table has : Craft(varchar) and OriginateDate(DateTime)

Oracle Table has: a Composite Primary key with the same columns i.e., Craft(Varchar2) and OriginateDate(DateTime)

I am using ADO.NET and doing this Transfer as shown in below algorithm

1. Open SQL Server connection

while(reader.read())

{

Read records from SQL server table

2. open oracle connection

3. start transaction

4. write into Oracle Table

 5. commit.transaction

6. close connections.

}

All working fine. I need help where I get same Craft and OrigianteDate from SQL Server. when I try to insert those into Oracle Table, it fails due to primary key  constraint. In order to handle this I need to

1) check SQL server record if  Craft && OrigianteDat ...