updating multiple rows in one sql query

Question

I have to update an arbitrary number of rows for a list of customers, when reminders are sent out to them. I can achieve this through a foreach loop, but I am sure there must be a way of doing this with on query.

This is what currently works

foreach($customer_id_arr as $c) mysqli_query($con,"UPDATE crm_customers SET customer_reminded=1 WHERE customer_id=$c");

How can I do that in one query?

Answer 1

You can leverage implode() for this:

mysqli_query($con,"UPDATE crm_customers SET customer_reminded=1 WHERE customer_id IN (" . implode(",",$customer_id_arr) . ")";

It's worth mentioning that you're likely wide open to SQL injection without using prepared statements.