oracle regexp_replace to remove commas between Quote - oracle

Question

Please can anybody help me out please. Have been trying for days to get a regexp_replace to remove commas between quotes irrespective of the commas position.
Example
cold, gold, "Block 12C, Jones Avenue, Broad Street, London", car
Expected Answer
cold, gold, "Block 12C Jones Avenue Broad Street London", car
thanks in advance

Answer 1

You could extract the contents within double quotes(REGEXP_SUBSTR), replace the commas, and stuff it back to the old string using replace.
select REPLACE (whole_str,quoted_str,REPLACE (quoted_str,',')) FROM
(
select
whole_str,
REGEXP_SUBSTR( whole_str, '^[^"]*("[^"]+")',1,1,NULL,1) quoted_str
FROM yourtable
);
DEMO
Note that this could also be done using INSTR,SUBSTR which could be more efficient, but hard to read.

Answer 2

You can use regexp_replace to get the desired output :
with t( id , val ) as(
select 1,'cold, gold, "Block 12C, Jones Avenue, Broad Street, London", car' from dual union
select 2,'"Block 12C, Jones Avenue, Broad Street, London", car, cold, gold' from dual )
select id, val value
from t
model dimension by( id ) measures( val )
rules iterate(100)( val[any] = regexp_replace(val[cv()],',(([^"]*"){2})*([^"]*"[^"]*)$',' \1\3') );
d E m O

Answer 3

I doubt that there is a single regular expression function that will achieve the desired result. The "obvious" line of attack is to chop the input string into pieces and delete commas from each double-quoted substring as needed. (Unless each string has at most ONE double-quoted substring, in which case the problem has easier answers - but judging from the sample input string, it is possible that the same needs to be done for input strings with an arbitrary number of double-quoted substrings.)
Here is a solution using a recursive WITH clause - so it requires Oracle 11.2 or higher. (For earlier versions, a solution with a CONNECT BY hierarchical query can be used instead.) I wrote it with regular expressions, as requested; if speed becomes an issue, it can be re-written with standard INSTR, SUBSTR and REPLACE functions.
In the first factored subquery (subquery in the WITH clause) I created a few more inputs, to test whether the solution returns the correct result in different situations.
with
inputs ( str ) as (
select 'cold, gold, "Block 12C, Jones Ave., London", car' from dual union all
select '"One, two, three","Four, five six,",' from dual union all
select 'No, double-quotes, in this, string' from dual union all
select 'No commas in "double quotes" here' from dual
),
r ( str, init, quoted, fin ) as (
select str, null, null, str
from inputs
union all
select str,
init || replace(quoted, ',') || regexp_substr(fin, '[^"]*'),
regexp_substr(fin, '"[^"]*"'),
regexp_substr(fin, '([^"]*"){2}(.*)', 1, 1, null, 2)
from r
where quoted is not null or fin is not null
)
select str, init as new_str
from r
where quoted is null and fin is null
;
STR NEW_STR
--------------------------------------------- -------------------------------------------
No, double-quotes, in this, string No, double-quotes, in this, string
cold, gold, "Block 12C, Jay Ave, London", car cold, gold, "Block 12C Jay Ave London", car
No commas in "double quotes" here No commas in "double quotes" here
"One, two, three","Four, five six,", "One two three","Four five six",