Billz

Please help me let me explain with this..... ``` purchase table id purchase_id product_id qty net_unit_cost created_at 1 1 1 10 10 2022-10-10 2 2 1 20 12 2022-10-10 Sale table sale_id product_id qty net_unit_price created_at 1 1 11 15 2022-10-10 ``` in this, if i sold '11' units then how can i subtract from the rows to get remaining units? i've to subtract '10' units from first row and '1' unit from second row. Please help how to calculate fifo in php

@davejplease help me.

Please help me let me explain with this..... purchase table id purchase_id product_id product_batch_id variant_id imei_number qty recieved purchase_unit_id net_unit_cost discount tax_rate tax total created_at updated_at 1 1 1 NULL NULL NULL 10 10 1 40 0 0 0 400 2022-10-01 14:37:01 2022-10-01 14:37:01 2 2 1 NULL NULL NULL 15 15 1 45 0 0 0 675 2022-10-01 14:39:09 2022-10-01 14:39:09 3 3 1 NULL NULL NULL 15 15 1 48 0 0 0 720 2022-10-01 14:40:44 2022-10-01 14:40:44 Sale Table sale_id product_id qty net_unit_price total created_at Edit Copy Delete 1 1 10 50 500 2022-10-01 14:37:22 Edit Copy Delete 2 1 10 50 500 2022-10-01 14:39:35 Edit Copy Delete 3 1 15 50 750 2022-10-01 14:41:12 Edit Copy Delete 4 1 5 50 250 2022-10-01 15:55:21 Edit Copy Delete 5 1 1 50 50 2022-10-03 15:02:43 Edit Copy Delete 6 1 1 40 40 2022-10-03 15:06:12 Edit Copy Delete 7 1 1 40 40 2022-10-03 15:06:15 in this, if i sold '11' units then how can i subtract from the rows to get remaining units? i've to subtract '10' units from first row and '1' unit from second row. Please help how to calculate fifo in php

hello davej i need your help.