Mysql How to update n rows using count function?

Question

In the following table, I want to set delete = true if the total records for same orgid exceed 500 and I want to do it according to createdate such that if records exceed 500 the old records get deleted and make total records 500 for that orgid.

here is my table

Table A
+----+-------+------------------+--------+------------+
| id | orgid | transactionvalue | delete | createdate |  
+----+-------+------------------+--------+------------+
|  1 |     1 |              123 | false  | 05-16-2020 |  
|  2 |     1 |              412 | false  | 07-16-2020 |  
|  3 |     2 |              762 | false  | 07-16-2020 |  
+----+-------+------------------+--------+------------+

Here is the query I am trying

update A set delete = true where orgid = 1 and (select count(*) as records from (select * from A order by createdate) as pseudotable)) >500

Answer 1

This query will update the oldest records that exceed the count of 500, so you keep 500 newest records for orgid = 1

update A 
set `delete` = true 
where orgid = 1 AND id IN (
SELECT id FROM  A where orgid = 1
order by createdate DESC
LIMIT 500,18446744073709551615);