SQL - Query Phonenumber that are stored inconsistently

Question

we a phonenumber field in our database and I would like to do a simple lookup query like:

SELECT * FROM TABLE WHERE Phonenumber = \'555123456\'

Answer 1

Since I don't know what RDBMS you're looking for, I'll give the most generic way:

phonenumber like '%5%5%5%1%2%3%4%5%6%'

This assumes that all phone numbers are at least equal length (in digits).