SQLite convert single row to multiple rows - sqlite

Question

SQLite
I want to convert single row value seperate by ',' to multiple rows
Example :
Single_Row
6,7,8,9,10,11,12,13,14,15,16
Result must be :
MultipleRows
6
7
8
9
10
12
13
14
15
16
I tried doing it with substr function but getting unexpected result
select
numbers.n,
substr(CbahiHSSpecialtyUnits.units,numbers.n,1)
from
numbers inner join CbahiHSSpecialtyUnits
on LENGTH(CbahiHSSpecialtyUnits.units)
- LENGTH(REPLACE(CbahiHSSpecialtyUnits.units, ',', ''))>=numbers.n-1
WHERE HsSubStandardID=22 and SpecialtyID=2 and numbers.n>0
order by numbers.n;
One good thing is I'm getting number of rows correct.. But the values that should be separated is wrong ..
Please note numbers table is I have created for indexing purpose, with the help of this post.
SQL split values to multiple rows

Answer 1

You can do it with a recursive CTE:
WITH cte AS (
SELECT SUBSTR(Units, 1, INSTR(Units || ',', ',') - 1) col,
SUBSTR(Units, INSTR(Units || ',', ',') + 1) value
FROM CbahiHSSpecialtyUnits
WHERE HsSubStandardID=22 AND SpecialtyID = 2
UNION ALL
SELECT SUBSTR(value, 1, INSTR(value || ',', ',') - 1),
SUBSTR(value, INSTR(value || ',', ',') + 1)
FROM cte
WHERE LENGTH(value) > 0
)
SELECT col
FROM cte
WHERE col + 0 > 0
Or, if you know the upper limit of the numbers is, say 20 and there are no duplicates among the numbers:
WITH cte AS (SELECT 1 col UNION ALL SELECT col + 1 FROM cte WHERE col < 20)
SELECT c.col
FROM cte c INNER JOIN CbahiHSSpecialtyUnits u
ON ',' || u.Units || ',' LIKE '%,' || c.col || ',%'
WHERE HsSubStandardID=22 AND SpecialtyID = 2
See the demo.
Results:
col
6
7
8
9
10
11
12
13
14
15
16

Answer 2

I got the solution
http://www.samuelbosch.com/2018/02/split-into-rows-sqlite.html
WITH RECURSIVE split(predictorset_id, predictor_name, rest) AS (
SELECT CbahiHSSpecialtyUnits.SpclUnitSerial, '', units || ',' FROM CbahiHSSpecialtyUnits WHERE HsSubStandardID=22 and SpecialtyID=2
UNION ALL
SELECT predictorset_id,
substr(rest, 0, instr(rest, ',')),
substr(rest, instr(rest, ',')+1)
FROM split
WHERE rest <> ''