Defaulting of DFF using SQL query

Hello,

I am trying to default the AR Transaction line DFF based on the value of Order line DFF.

We have a DFF Project Code at order line level. We want to populate DFF at Invoice line level with the same value.

I am using the following SQl Query to default the DFF value, but DFF at invoice line is not getting defaulted Can you please check if the query used is correct or suggest on the same.

Select OL.attribute6 from oe_order_headers_all OH, OE_ORDER_LINES_ALL OL where OL.LINE_NUMBER = :TLIN_LINES.SALES_ORDER_LINE and OH.ORDER_NUMBER = :TLIN_LINES.SALES_ORDER and OL.HEADER_ID = OH.HEADER_ID