Mysql IN对字符串，整数和PDO的行为有所不同

Question

I am updating an old PHP script to use PDO, and I am having trouble duplicating the original behavior.

The problem appears to be related to a neat little feature of the IN comparison that does not work with strings.

Given this table:

CREATE TABLE `my_categories` (
  `name` VARCHAR(255) NULL,
  `categories` VARCHAR(255) NULL);

INSERT INTO my_categories (name, categories) VALUES
('Joe', '575'),
('Bob', '576'),
('Jim', '577'),
('Daisy','576,577'),
('Billy','576,597');

I can use this following SQL to match all the rows as required:

SELECT * as test FROM my_categories WHERE categories IN (575,576,577) 
 name   categories
 Joe    575
 Bob    576
 Jim    577
 Daisy  576,577
 Billy  576,597

However, with the slightest modification, Daisy and Billy are dropped from the results:

SELECT * as test FROM my_categories WHERE categories IN ('575','576','577')
 Joe    575
 Bob    576
 Jim    577

My problem is that I cannot duplicate the results in the first test at all using prepared statements in PDO.

Why is the behavior different, how can I get that functionality from a prepared statement, and is there a better way to compare "dumb" comma separated lists in a way to match all the given test cases?

Mysql Fiddle: http://sqlfiddle.com/#!9/798faa/2