I have a string and I would like to split that string by delimiter at a certain position.
For example, my String is F/P/O and the result I am looking for is:
Therefore, I would like to separate the string by the furthest delimiter.
Note: some of my strings are F/O also for which my SQL below works fine and returns desired result.
The SQL I wrote is as follows:
SELECT Substr('F/P/O', 1, Instr('F/P/O', '/') - 1) part1, Substr('F/P/O', Instr('F/P/O', '/') + 1) part2 FROM dual and the result is:
Why is this happening and how can I fix it?
2 Answers
Therefore, I would like to separate the string by the furthest delimiter.
I know this is an old question, but this is a simple requirement for which SUBSTR and INSTR would suffice. REGEXP are still slower and CPU intensive operations than the old subtsr and instr functions.
SQL> WITH DATA AS 2 ( SELECT 'F/P/O' str FROM dual 3 ) 4 SELECT SUBSTR(str, 1, Instr(str, '/', -1, 1) -1) part1, 5 SUBSTR(str, Instr(str, '/', -1, 1) +1) part2 6 FROM DATA 7 / PART1 PART2 ----- ----- F/P O As you said you want the furthest delimiter, it would mean the first delimiter from the reverse.
You approach was fine, but you were missing the start_position in INSTR. If the start_position is negative, the INSTR function counts back start_position number of characters from the end of string and then searches towards the beginning of string.
You want to use regexp_substr() for this. This should work for your example:
select regexp_substr(val, '[^/]+/[^/]+', 1, 1) as part1, regexp_substr(val, '[^/]+$', 1, 1) as part2 from (select 'F/P/O' as val from dual) t Here, by the way, is the SQL Fiddle.
Oops. I missed the part of the question where it says the last delimiter. For that, we can use regex_replace() for the first part:
select regexp_replace(val, '/[^/]+$', '', 1, 1) as part1, regexp_substr(val, '[^/]+$', 1, 1) as part2 from (select 'F/P/O' as val from dual) t And here is this corresponding SQL Fiddle.
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