RE: edit all posted trade agreements lines for items
Hi M.Yoko
Let's say you have 50 Trade agreement prices active, and they all have a blank To date. My guess is that you want to end up with 50 active Trade agreement prices, but the To date populated (all having the same To date).
Here's what you do!
Create a Trade agreement journal, and open the Lines form. Press the Select button, and populate the dialogue like this:

This will bring in all Sales price trade agreements. In my example, this is 50 lines. None of these lines has a To date.
Press Copy and revise, and fill the To date that you want:

Now you have 100 lines. The first 50 have no To date, and the last 50 have the same To date.
Use the Advanced filter or sort option to show only lines with no To date (I used To date = ""). You should now only see 50 lines in your journal. Select all the lines and press Alt + F9 to delete them from the Journal. You will now see no lines. Remove the Filter. You should now see 50 lines, all which have a To date. Post the Journal.
Create a new Trade agreement journal. Open the lines form. Press Select, and use the same criteria as before. You now see 100 lines. Use the Advanced filter or sort option to show only lines where the To date is not blank (I used To date = !""). You should now only see 50 lines. Select all the lines and Press Alt + F9 delete them from the Journal. You will now see no lines. Remove the filter. You should now see 50 lines, all which have no To date. Press Select all agreements to be deleted. Post the Journal. This will delete the prices which have no To date, leaving you with only the prices which have a To date.
This seems even harder than it was in 2012!