Match the different quantity as per posting date from different table

[Vince_CH]

Dear Experts,

I am stuck with a question for a while, hope you can give me a hand. as below, I have three tables, first is the purchase order list with PO number, material number etc listed, second table contains the posted date (receipt date), with possibly received in different batch as per date differently.  Last is the production order which requires the same materials.

I have set like red circled, PO number & material number as the key, to link the three tables.

My question, also problem now is, in the last column of production order list, post_date, it is supposed to extract the real receipt date as second table, but unfortunately it is not appearing, as there are two posting dates for this case. so how can I allocate the first receipt date for the production order, and when the quantity is exceeding, then second receipt date is to fill in?  hope I explain the case clearly, if you have any questions, kindly please let me know, thanks a lot in advance.

[Vince_CH]

Dear All,
it seems to be a complicated case.
Does someone can help on this?

thanks in advance.

BR Vince