Billz

i want to subtraction sum of all rows in php. can you write code?

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 2022-10-1 2 2 1 20 12 2022-10-10 Sale table sale_id product_id qty net_unit_price created_at 1 1 11 15 2022-10-15 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

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