----- Original Message -----
From: "Michael Stassen" <[EMAIL PROTECTED]>
To: "Rhino" <[EMAIL PROTECTED]>
Cc: "abhishek jain" <[EMAIL PROTECTED]>; <mysql@lists.mysql.com>
Sent: Saturday, November 19, 2005 1:11 PM
Subject: Re: Mysql Finding the country name from country prefix
Rhino wrote:
----- Original Message ----- From: "abhishek jain" <[EMAIL PROTECTED]>
To: <mysql@lists.mysql.com>
Sent: Saturday, November 19, 2005 8:10 AM
Subject: Mysql Finding the country name from country prefix
Hi Friends,
I have a ticky mysql problem.
I need to find the country name from the country prefix so eg. i have a
mysql table with prefix and name as the coumns and with datas like :
Prefix, Name
1 USA
11 XYZ
44 UK
91 India
92 Pakistan
123 ZXF
and i have a number like 911122334455 and i need t match that to india.
I cannt do that directly by this statement select name from
country_table where prefix='91'; for the simple reason as i do not have
the length or the no. of digits the prefix is beforehand.
Pl. help me out.
Quick help will be appreciated.
You are not explaining your problem very clearly at all, particularly why
you think this is a MySQL problem.
It looks to me as if you are trying to parse a phone number and determine
from the first few digits what country that phone number represents. You
already have a table that gives you the country code for each country and
it shows clearly that 91 is the country code for India. As for the length
of the country code, surely you can easily calculate that 91 has two
digits in it.
If you are saying that you have only a string of digits and need to
determine the country in which that phone number originates without any
further information, all I can say is good luck. The fact is that people
write their phone numbers in many different ways. Here in Canada, if I'm
giving my number to someone who lives within my city or region, I'm
likely to give them only the last seven digits, e.g. 5551212. If I wanted
to give my number to someone farther away in Canada, the US, or the
Caribbean, I'd give them 5195551212 since we all share the same country
code, 1. If I wanted to give my number to someone in some other foreign
country, I'd give them 15195551212. So, right away, you have three
different ways to express the phone number all of which are accurate and
complete in their own context. If you parsed the first example, you might
assume that I am in Brazil, because '55' is the country code for Brazil.
(Country codes '5' and '555' are not in use at present.) If you parsed
519-555-1212, you wouldn't find anything because there is no country code
'5', '51', or '519' currently in use. If you tried to parse
'15195551212', you'd think I was in the US, Canada, or one of the
Caribbean countries since '1' is the code for those countries. (There is
is no '15' or '151' country code at present.) Therefore, the phone number
_by itself_ is next to useless to you unless you are absolutely certain
that the phone number is complete and includes the country code,
area/city code and local number.
None of that is a MySQL problem. The problem lies in your data
acquisition technique. If you have to parse phone numbers, the input
forms you use have to ensure that the user supplies the entire phone
number; ideally, that number would be supplied in different fields, one
of which would be the country code. Then you would have no problem except
making sure that the user has supplied their own phone number and not
someone elses. (The number I used in my examples, 15195551212, is the
directory assistance phone number for my area, not my own phone number.)
So, unless I've misunderstood what you are asking, I don't think we can
help you very much. There is no function in MySQL or any other database I
have used that can calculate the country code accurately given only a
phone number that may or may not be complete.
Rhino
Everything you say is true, if the list contains incomplete phone numbers,
but why do you assume that is the case? The OP said no such thing. The
question is, given a string such as '911122334455', how do you find rows
in the country_table where the prefix column matches the beginning of the
string? I think that amounts to, how do I do string comparisons in mysql?
Actually, it is the _original poster_ that is assuming the phone number is
complete; I'm just trying to warn him that the problem becomes nearly
insoluble if the phone number _isn't_ complete.
Even if the number is complete, if we don't know the country associated with
the phone number, which is the whole problem, how many digits of the number
are the country code if the country code can be 1 thru 4 digits?
Rhino
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