Issue with RegExp matching a phone number format in query

Question

I am trying to write a RegExp for MySQL that will only return the following 3 phone formats:

+1 000-000-0000 x0000

+1 000-000-0000

000-000-0000 x0000

000-000-0000

So basically:

+[any number of digits][space][any three digits]-[any three digits]-[any four digits][space][x][any number of digits]

The country code and the extension are optional. I am new to these but I would think this should return at least a number including both country code and extension options, but I get 0 results when I execute it.

\x2B[0-9]*\x20[0-9]{3}\-[0-9]{3}\-[0-9]{4}\x20x[0-9]+|
\x2B[0-9]*\x20[0-9]{3}\-[0-9]{3}\-[0-9]{4}|
[0-9]{3}\-[0-9]{3}\-[0-9]{4}

Can someone tell me why I am getting 0 results even though I have records like +1 555-555-5555 x5555 in my db. Also what is the syntax to make the country code and the extension are optional

Please note I am using [0-9] because I am querying a text field and \\d didn't seem to return anything even when my criteria was something simple like \\d*

Answer 1

So, as a joint effort, turns out the answer is here:

SELECT * FROM table 
WHERE field 
REGEXP '(^[+][0-9]+\ )?([0-9]{3}\-[0-9]{3}\-[0-9]{4})(\ x[0-9]+$)?'

First was the fact that character codes in mysql (x20, x2B and the like) are not allowed. Next important step was the use of parenthesis and the "?" token to make the different sections optional.

============

I think the issue is the lack of parenthesis to define the subexpressions.

This seems to work out for me, though it doesn't look real pretty:

SELECT '+1 000-000-0000 x0000' REGEXP '^(([+][0-9]*\[ ][0-9]{3}\-[0-9]{3}\-[0-9]{4}[ ]x[0-9]+)|())$'

as does

SELECT '' REGEXP '^(([+][0-9]*\[ ][0-9]{3}\-[0-9]{3}\-[0-9]{4}[ ]x[0-9]+)|())$'

as does (plain phone number):

SELECT '555-555-5555' REGEXP '^(([+][0-9]*\[ ])*[0-9]{3}\-[0-9]{3}\-[0-9]{4}([ ]x[0-9]+)*)|())$'

EDIT: (same regexp as above, but testing against version w/ country code and extension):

SELECT '+1 555-555-5555 x55' REGEXP '^(([+][0-9]*\[ ])*[0-9]{3}\-[0-9]{3}\-[0-9]{4}([ ]x[0-9]+)*)|())$'

When I try yours:

SELECT '+1 000-000-0000 x0000' REGEXP '\x2B[0-9]*\x20[0-9]{3}\-[0-9]{3}\-[0-9]{4}\x20x[0-9]+|' 

I get:

1139 - Got error 'empty (sub)expression' from regexp