在执行之前我怎么知道有多少行会更新受影响的sql

谁可以使用解释查看在下面的 sql 中将选择多少条记录：

explain select * from products 

but expain is not for update and delete command.
In php, I want to update an table using a sql , I want to check weather this sql will update only row or many rows , if many rows affected , this sql is not allow to run for preventing the table misoperation.
so how can I know how many rows will this update sql affected before I execute it?

update products set products_model = 'hello' where products_id = '1'

运行查询

SELECT COUNT(id) AS will_affect_rows_count FROM products WHERE products_id = '1'

这将为您提供将受 UPDATE 查询影响的行数。

请问为什么这个表中的产品可以有重复的 products_id？