How to remove currency symbol from price column? - sql

Question

I have a price column which is string and has price for the product from all over the world , now When I try to perform any operation like sum I am getting error.
So my question is how can I remove currency symbol from price column for all the countries?
Here is my sample input:-
locale price
cs_CZ 2462475,38 K
da_DK kr 591.872,50
de_AT 267,70
de_CH CHF 1'998.99
de_DE 1.798,09
en_AE AED7,236.20
en_AU $1,699.00
en_BD Tk999,999.00
en_HK HK$6,188.00
en_HU Ft344,524,655.48
tr_TR 2.344.697,66 TL

Answer 1

Postgres offloads most locale handling to the operating system. So the Postgres currency conversion routines will only work for you if the OS understands the locale names, and your price strings match its expected format.
For example, Windows won't accept da_DK as a locale, and even if it did, it will not accept the string kr 591.872,50, as it expects the Danish currency symbol to be kr. instead of kr.
That said, I think this should work reasonably well on a Linux-based server:
CREATE FUNCTION convert_currency(amount TEXT, locale TEXT) RETURNS NUMERIC AS
$$
BEGIN
PERFORM set_config('lc_monetary', locale || '.UTF-8', True);
RETURN amount::MONEY::NUMERIC;
END
$$
LANGUAGE plpgsql
SET lc_monetary TO DEFAULT;

Answer 2

You seem to have both decimal point and decimal comma but always two decimals (hopefully in the rest of the data too).
You can start by putting those values in a value list for testing (adding extra single quotes where needed).
Then you have to trim out spaces and letters with regular expressions. In the inner SELECT you get the substring with single quotes and commas for thousand separators still in it.
In the outer SELECT you replace the decimal commas in the decimal side and strip out thousand separators on the integer side. The result is cast to type numeric with which you can count sums etc.
SELECT (
regexp_replace(left(substring, length(substring) -3),'[.,'']','','g')
|| replace(right(substring, 3),',','.'))::numeric,
*
FROM (
SELECT substring(column1 from '(([0-9]+[,.''])*[0-9]+[.,][0-9]{2})[^0-9]*$'),
column1
FROM (
VALUES ('2462475,38 K'),
('kr 591.872,50'),
('267,70'),
('CHF 1''998.99'),
('1.798,09'),
('AED7,236.20'),
('$1,699.00'),
('Tk999,999.00'),
('HK$6,188.00'),
('Ft344,524,655.48'),
('2.344.697,66 TL')
) currencies
) sq1;
The following is the whole answer compatible with 9.0 version of PostgreSQL (no left() or right() functions used). Also values list is replaced with a SELECT query that you can replace with your own table and column. Finally it's all been enclosed in a SELECT query that demonstrates the use of the sum-function.
SELECT sum(numeric) FROM (
SELECT (
regexp_replace(substr(substring, 0, length(substring) -3),'[.,'']','','g')
|| replace(substr(substring, length(substring) -3, length(substring)),',','.'))::numeric,
*
FROM (
SELECT substring(column1 from '(([0-9]+[,.''])*[0-9]+[.,][0-9]{2})[^0-9]*$'),
column1
FROM (
SELECT column1 FROM your_table
) currencies
) sq1
) sq2