Hi, anyone knows why the quantity column is negative on the item line on a customer invoice (in the GUI it is positive)?

select quantity from transactionline where transaction = 12345

Is there COGS on the GL impact of the invoice? A standalone (not related to an SO) invoice containing an inventoried item will decrement inventory and hit COGS. Since there's inventory going out the door, that could be the reason for the -1. Likely you'd have two lines in the DB for that scenario>+1 for the revenue and -1 for the COGS/inventory.

There are no transactionlines on that invoice with a positive quantity

What's the account type it's hitting? I've seen this with expense account items before.

the account type is AcctRec (accounts receivable)