MySQL查询中的单引号不适用于concat（）

你需要concat()为like：

SELECT osid, os_name,
       (SELECT count(*)
        FROM game_game
        WHERE concat(',', os, ',') LIKE CONCAT('%,', os.osid, ',%')
       ) as game_count
FROM game_os AS os
ORDER BY osid;

但是，您也可以使用编写此代码find_in_set()，因为您使用逗号作为分隔符：

SELECT osid, os_name,
       (SELECT count(*)
        FROM game_game
        WHERE find_in_set(os.osid, os) > 0
       ) as game_count
FROM game_os AS os
ORDER BY osid;