MySQL: Query depending on the value, not the name of the column

As already said, I think you need to think about your table vertically (your 500 columns should actually be 500 rows of a table, with three columns ... or more, but not 500! :) Your question seemed curious to me, so I set out to make a fiddle of a possible solution.

The query will look for any value other than 100 in all rows of your table.

SQL Fiddle

MySQL 5.6 Schema Setup :

CREATE TABLE columnas
    ('id' int, 'columna_num' int, 'valor' int)
;

INSERT INTO columnas
    ('id', 'columna_num', 'valor')
VALUES
    (1,1,100),
    (2,2,60),
    (3,3,100),
    (4,4,35),
    (5,200,100),
    (6,201,100),
    (7,300,100),
    (8,302,100),
    (9,400,100),
    (10,403,100),
    (11,500,56)
;

Query 1 Columns other than 100:

SELECT
  columna_num, valor
FROM
  columnas
WHERE 
  valor <> 100

Results :

| columna_num | valor |
|-------------|-------|
|           2 |    60 |
|           4 |    35 |
|         500 |    56 |

Query 2 All columns up to 500 (test) :

SELECT
  columna_num, valor
FROM
  columnas

Results :

| columna_num | valor |
|-------------|-------|
|           1 |   100 |
|           2 |    60 |
|           3 |   100 |
|           4 |    35 |
|         200 |   100 |
|         201 |   100 |
|         300 |   100 |
|         302 |   100 |
|         400 |   100 |
|         403 |   100 |
|         500 |    56 |

Good morning. This more than an answer is an annotation.

If all of your 500 columns use the same type of data, you can change the structure of your table. From what I understand, your table should look like this:

| id |columna 1 | columna 2 | columna 3 | columna 4 | columna 5 | columna 6 | ...
| 1  |1         | 9         | 6         | 3         | 8         | 4         |
| 2  |2         | 4         | 7         | 2         | 6         | 6         |
| 3  |3         | 9         | 5         | 5         | 5         | 9         |
| 4  |6         | 5         | 12        | 7         | 8         | 9         |

You must understand that each row must have a unique identifier. Then you can transform it to a table like the following:

| id | numero_columna | valor
| 1  | 1              | 1
| 1  | 2              | 9
| 1  | 3              | 6
| 1  | 4              | 3
| 2  | 1              | 2
| 2  | 2              | 4
| 2  | 3              | 7
| ...| ...            | ...

Where the primary has the form PRIMARY KEY (id, numero_columna) .

Then your query is like:

SELECT valor FROM tabla WHERE numero_columna in (2, 4, 500) AND valor <> 100;