Pls help me..Any given idea is welcome. | SoloLearn: Learn to code for FREE!


Pls help me..Any given idea is welcome.

Am been working on this project. I created a table called drugs & created another table called orders... Now i have like quantity as a column in my drugs table.. In orders table how can someone makes an order of a drug so it should subtract it from the qauntity column of the drug table... E.g Drugs table.... Has a column named quantity... We have quantity as 5... The how can one makes 1 order so it should subtract it from 5 to remainder 4 to be left in quantity... Pls any observation thanks for listening.

2/27/2020 4:39:13 AM

Nwankwo Valentine

5 Answers

New Answer


the only way to decrease quantity is to update: $result = $conn->query("select quantity from drugs where columnname = columnvalue "); if($row = $result->fetch_assoc()){ $newqty = $row['quantity'] - 1; $query = "update drugs set quantity = $newqty where columnname = columnvalue "; if( $conn->query($query)){ echo "updated"; }else{ echo "fail to updated"; } }


What are you using this in? php or js?


Coder's Crux is php


Well then, you can simply run a query to the table called drugs, using mysqli_query() and then run a query to deduct the quantity of drugs from the current stock. EDIT: Also, what use is the drugs table? Do you have multiple rows with different types of drugs in them?


Soo Zhan Nam Thank you