Extracting dollar amounts from existing sql data? - regex

Question

I have a field with that contains a mix of descriptions and dollar amounts. With TSQL, I would like to extract those dollar amounts, then insert them into a new field for the record.
-- UPDATE --
Some data samples could be:
Used knife set for sale $200.00 or best offer.
$4,500 Persian rug for sale.
Today only, $100 rebate.
Five items for sale: $20 Motorola phone car charger, $150 PS2, $50.00 3 foot high shelf.
In the set above I was thinking of just grabbing the first occurrence of the dollar figure... that is the simplest.
I'm not trying to remove the amounts from the original text, just get their value, and add them to a new field.
The amounts could/could not contain decimals, and commas.
I'm sure PATINDEX won't cut it and I don't need an extremely RegEx function to accomplish this.
However, looking at The OLE Regex Find (Execute) function here, appears to be the most robust, however when trying to use the function I get the following error message in SSMS:
SQL Server blocked access to procedure 'sys.sp_OACreate' of component
'Ole Automation Procedures' because this component is turned off as
part of the security configuration for this server. A system
administrator can enable the use of 'Ole Automation Procedures' by
using sp_configure. For more information about enabling 'Ole
Automation Procedures', see "Surface Area Configuration" in SQL Server
Books Online.
I don't want to go and changing my server settings just for this function. I have another regex function that works just fine without changes.
I can't imagine this being that complicated to just extract dollar amounts. Any simpler ways?
Thanks.

Answer 1

CREATE FUNCTION dbo.fnGetAmounts(#str nvarchar(max))
RETURNS TABLE
AS
RETURN
(
-- generate all possible starting positions ( 1 to len(#str))
WITH StartingPositions AS
(
SELECT 1 AS Position
UNION ALL
SELECT Position+1
FROM StartingPositions
WHERE Position <= LEN(#str)
)
-- generate possible lengths
, Lengths AS
(
SELECT 1 AS [Length]
UNION ALL
SELECT [Length]+1
FROM Lengths
WHERE [Length] <= 15
)
-- a Cartesian product between StartingPositions and Lengths
-- if the substring is numeric then get it
,PossibleCombinations AS
(
SELECT CASE
WHEN ISNUMERIC(substring(#str,sp.Position,l.Length)) = 1
THEN substring(#str,sp.Position,l.Length)
ELSE null END as Number
,sp.Position
,l.Length
FROM StartingPositions sp, Lengths l
WHERE sp.Position <= LEN(#str)
)
-- get only the numbers that start with Dollar Sign,
-- group by starting position and take the maximum value
-- (ie, from $, $2, $20, $200 etc)
SELECT MAX(convert(money, Number)) as Amount
FROM PossibleCombinations
WHERE Number like '$%'
GROUP BY Position
)
GO
declare #str nvarchar(max) = 'Used knife set for sale $200.00 or best offer.
$4,500 Persian rug for sale.
Today only, $100 rebate.
Five items for sale: $20 Motorola phone car charger, $150 PS2, $50.00 3 foot high shelf.'
SELECT *
FROM dbo.fnGetAmounts(#str)
OPTION(MAXRECURSION 32767) -- max recursion option is required in the select that uses this function

Answer 2

This link should help.
http://blogs.lessthandot.com/index.php/DataMgmt/DataDesign/extracting-numbers-with-sql-server
Assuming you are OK with extracting the numeric's, regardless of wether or not there is a $ sign. If that is a strict requirement, some mods will be needed.