Enhance MySQLi Query for Data Update

Job ID: 37637605

Budget: $10 – $30 USD

Hello everyone
i am working on inventory system i have a table by name of stockIN with columns name itemName,quantity,remQuantity , and i have data in the table ex: item name computer with quantity 10,3,20,1,25 in different rows now if some one ask for 37 computers i want to stock out them from these rows and update the remQuantity = quantity-stockOut.
i am using php and mysql