在一个sql查询中更新多行

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 .

Answer 2

Not the nicest way to escape data, but you can do:

mysqli_query($con,"UPDATE 
    crm_customers 
  SET 
    customer_reminded=1 
  WHERE customer_id IN (".implode(',', array_map(function($c){return $con->real_escape_string($c);a},$customer_id_arr)).")");

Answer 3

Let's say you need to update customer ID's 1, 2, 3, 4 and 5:

UPDATE crm_customers 
SET customer_reminded = 1 
WHERE customer_id IN (1, 2, 3, 4, 5)

You could even use subqueries in your IN clause. Let's say you wanted to set customer_reminded=1 on all records where customer_reminded==0. Something like:

UPDATE crm_customers SET customer_reminded = 1 
WHERE customer_id IN 
    (SELECT customer_id 
    FROM crm_customers 
    WHERE customer_reminded == 0)