Question

I’ve got a wonderfully fun little SQL problem to solve today and thought I’d ask the community to see what solutions you come up with.

We’ve got a really cool email to text service that we use, you just need to send an email to [e-mail] and it will send a text message to the desired phone number.

For example to send a text to 0790 0006006, you need to send an email to [e-mail], pretty neat huh?

The problem is with the phone numbers in our database. Most of the phone numbers are fine, but some of them have “rubbish” mixed in with the phone number.

Take these wonderful examples of the rubbish you need to deal with (I’ve anonymised the phone numbers by placing zeroes in):

07800 000647(mobile)
07500 000189 USE 1ST
SEE NOTES
07900 000415 HO ONLY
try 1st 0770 0000694 then home
07500 000465 Cannot

Requirements

The solution needs to be in SQL (for MS SQL server).

So the challenge is as follows, we need to get the phone number without spaces, and without any of the rubbish seen in the samples.

For example:

This:

try 1st 0770 0000694 then home

Should become this:

07700000694

Anything without a phone number in it (e.g. “SEE NOTES”) should be null.

UPDATE:

Thanks for the great responses! We’ve had some interesting answers, but seeing as none of the SQL answers have had any votes it’s a bit hard to pick a favourite. I’d have rather seen a clear favourite picked by the community.

I’ll let the question mature a little more and see if any votes come in before I award an answer.

Answer 1

Assuming that yopur phones always start with ’07’ and the length is 12 characters you can try something like this:

DECLARE @Number varchar(50)

--SET @Number='07800 000647(mobile)'
--SET @Number='07500 000189 USE 1ST'
--SET @Number='SEE NOTES'
--SET @Number='07900 000415 HO ONLY'
--SET @Number='try 1st 0770 0000694 then home'
SET @Number='07500 000465 Cannot '



SELECT REPLACE(SUBSTRING(@Number, case when CHARINDEX ('07',@Number ) =0 then Null 
else CHARINDEX ('07',@Number )end , 12),' ','')

First of all, finding the starting point of the ’07’ string, then, if it is 0 (‘SEE NOTES’), return Null. After that, getting the 12 characters of the number.
Lastly, replacing the spaces…