hi there, hope in your help.
  1. if tried the query #1 I have for output 22 rows in set
  2. if tried the query #2 I have for output 16 rows in set

Why?
Where does the row with output null ?
thank you.

query #1
Code:
mysql> SELECT
	ID,
	output
FROM
	tbl_0
WHERE
	1
AND ID IN (
	492,
	852,
	2713,
	4159,
	4498,
	5258,
	5477,
	5594,
	5760,
	6404,
	6419,
	8305,
	8816,
	9863,
	10363,
	10401,
	10448,
	10449,
	10450,
	11138,
	11201,
	11301
);
+-------+--------+
| ID    | output |
+-------+--------+
|   492 |        |
|   852 | 01     |
|  2713 | 01     |
|  4159 | 01     |
|  4498 |        |
|  5258 | 01     |
|  5477 | 01     |
|  5594 | 01     |
|  5760 |        |
|  6404 |        |
|  6419 |        |
|  8305 | 01     |
|  8816 | 01     |
|  9863 | 01     |
| 10363 | 01     |
| 10401 | 01     |
| 10448 | 01     |
| 10449 | 01     |
| 10450 | 01     |
| 11138 | 01     |
| 11201 | 01     |
| 11301 |        |
+-------+--------+
22 rows in set
query #2
Code:
mysql> SELECT
	ID,
	output
FROM
	tbl_0
WHERE
	FIND_IN_SET('01', output) > 0
OR FIND_IN_SET('02', output) > 0
OR FIND_IN_SET('03', output) > 0
OR FIND_IN_SET('04', output) > 0
OR FIND_IN_SET('', output) > 0
OR FIND_IN_SET(NULL, output) > 0
OR ISNULL(output)
OR output IS NULL
ORDER BY
	ID ASC;
+-------+--------+
| ID    | output |
+-------+--------+
|   852 | 01     |
|  2713 | 01     |
|  4159 | 01     |
|  5258 | 01     |
|  5477 | 01     |
|  5594 | 01     |
|  8305 | 01     |
|  8816 | 01     |
|  9863 | 01     |
| 10363 | 01     |
| 10401 | 01     |
| 10448 | 01     |
| 10449 | 01     |
| 10450 | 01     |
| 11138 | 01     |
| 11201 | 01     |
+-------+--------+
16 rows in set