Select data from single column as multiple record - mysql

Question

I have the following table structure in a mysql database.
id | files | status
1 a.pdf,b.pdf,c.pdx 1
2 d.pdf,e.pdf.g.pdf 2
3 x.pdf,k.pdf,y.pdf 1
As you can see, the attachments are all stored on a single line.
My query is supposed to select all rows where status = 1 so i'm expecting the data in the following format.
1 1 a.pdf 1
2 1 b.pdf 1
3 1 c.pdf 1
4 3 x.pdf 1
5 3 k.pdf 1
6 3 y.pdf 1
Unfortunately, I am unsure which operator I can use to accomplish this. I'm aware SQL has pivot but i doubt even that can address my issue.
As a result, I would appreciate if I could get any help in the condition of the select query.
Regards

Answer 1

Try this:
SET #row_num = 0;
SELECT
(#row_num := #row_num + 1) ROW_NUM,
id,
SUBSTRING_INDEX(SUBSTRING_INDEX(files, ',', idx), ',', -1) FileName,
status
FROM
test
JOIN
(SELECT 1 idx UNION ALL SELECT 2 idx UNION ALL SELECT 3 idx UNION ALL SELECT 4 idx UNION ALL SELECT 5 idx) idxs
on idxs.idx - 2 < LENGTH(files) - LENGTH(REPLACE(files, ",", ""))
WHERE status = 1
;
Just add as many indexes as your max count of files in a string.
Note that there should be no comma fater last filename. This is magic -2 is responsible for.

Answer 2

Consider the following...
I have a table (ints) of integers (0-9)...
DROP TABLE IF EXISTS my_table;
CREATE TABLE my_table
(id SERIAL PRIMARY KEY
,files VARCHAR(100) NOT NULL
,status INT NOT NULL
);
INSERT INTO my_table VALUES
(1,'a.pdf,b.pdf,c.pdx',1),
(2,'d.pdf,e.pdf,g.pdf',2),
(3,'x.pdf,k.pdf,y.pdf',1);
SELECT DISTINCT id
, SUBSTRING_INDEX(SUBSTRING_INDEX(files,',',i2.i*10+i1.i+1),',',-1) file
, status
FROM my_table
, ints i1
, ints i2
WHERE status = 1
ORDER
BY id, i2.i*10+i1.i;
+----+-------+--------+
| id | file | status |
+----+-------+--------+
| 1 | a.pdf | 1 |
| 1 | b.pdf | 1 |
| 1 | c.pdx | 1 |
| 3 | x.pdf | 1 |
| 3 | k.pdf | 1 |
| 3 | y.pdf | 1 |
+----+-------+--------+