PHP Update or Insert Command, while loop with sql created columns with defaults

General information for the website: Internal Intranet System Num. of web pages/modules: 1 Description of every page/module: The page: Editable Excel like spreadsheet, showing cust_number, Client_number, Item_number, with dates summed into month columns. With I Save button that executes UpdateCommand. Description of requirements/features: I need an Update & Insert Command to run a while loop, based on Cust_number, Client_number, item_number and a column date depending what column it is in. Extra services needed: 3rd party integration Extra notes: Attached picture is what the grid looks like, Example of column structure: SELECT cust_number, Client_number, item_number, Sum (CASE WHEN date BETWEEN '2017-01-01' AND '2017-01-31' THEN cases else 0 end) as Jan