When two tables in the load script have the same field names , they get concatenated automatically. So as stalwar1 mentioned, you need to explicitly use the NoConcatenate key word before the load of the second table.
Thnaks and Regards,
If you are expecting to have association between the various IDs in the link table, then you will be disappointed with the approach above (including the proposed fixes). Simply concatenating the ID fields will not create any associations as the other ID fields will all be null. For example, when you load INV_ID, all the other ID fields are filled with null values for the rows containing INV_ID. Likewise, the rows containing PART_ID will have null values in the other fields. So if you select an invoice value (linked via INV_ID), you will exclude all values of all the other links.
Presumably, your data sources for invoices and orders contain references to customer, part numbers, etc. You will need to create the link table by joining these on the appropriate fields or bringing in the associations. Something like:
LOAD DISTINCT ORDERID,
LOAD DISTINCT OPO_OPORDERID,
LOAD DISTINCT INV_ID,
JOIN LOAD DISTINCT // add parts not already loaded
JOIN LOAD DISTINCT // add customers not already loaded
If that is not right, I suggest that you shat more details about your data sctructure and what associations you need. For example, are invoices linked to orders?