I have a string in Oracle database, my string is: 'bbb;aaa;qqq;ccc'
I used regexp for split my string:
select distinct trim(regexp_substr('bbb;aaa;qqq;ccc','[^;]+', 1,level) ) as q
from dual
connect by regexp_substr('bbb;aaa;qqq;ccc', '[^;]+', 1, level) is not null ;
I want to split it in order, I expected the below output always:
bbb
aaa
qqq
ccc
because order of the subString are very important for me. but the result of this query is not in order:
qqq
aaa
bbb
ccc
You don't need a DISTINCT to get your result; besides, to get the result in a given order, all you need is an ORDER BY clause:
select trim(regexp_substr('bbb;aaa;qqq;ccc','[^;]+', 1,level) ) as q
from dual
connect by regexp_substr('bbb;aaa;qqq;ccc', '[^;]+', 1, level) is not null
order by level
If you do need DISTINCT:
WITH your_data( value ) AS (
SELECT 'bbb;aaa;qqq;ccc;aaa;eee' FROM DUAL
),
positions ( string, lvl, start_pos, end_pos ) AS (
SELECT value, 1, 1, INSTR( value, ';', 1, 1 ) FROM your_data
UNION ALL
SELECT string, lvl + 1, end_pos + 1, INSTR( string, ';', 1, lvl + 1 )
FROM positions
WHERE end_pos > 0
),
substrings ( string, substring, lvl, start_pos ) AS (
SELECT string,
DECODE( end_pos, 0, SUBSTR( string, start_pos ), SUBSTR( string, start_pos, end_pos - start_pos ) ),
lvl,
start_pos
FROM positions
)
SELECT string,
substring,
lvl
FROM substrings
WHERE INSTR( ';' || string || ';', ';' || substring || ';' ) = start_pos;
Output:
STRING SUBSTRING LVL
----------------------- ----------------------- ----------
bbb;aaa;qqq;ccc;aaa;eee bbb 1
bbb;aaa;qqq;ccc;aaa;eee aaa 2
bbb;aaa;qqq;ccc;aaa;eee qqq 3
bbb;aaa;qqq;ccc;aaa;eee ccc 4
bbb;aaa;qqq;ccc;aaa;eee eee 6
