clean tel number

Thank you for the method you've posted.

Which one is faster? Yours?

You can test them, but both methods go through the string character by character multiple times.

A simple method that goes through only once would be something like

<?php

$oldstring = "%(913) 285-4589,(812)873-8432";

$newstring="";
for ($i=1;$i<=50;$i++)
{
  $char = SUBSTR($oldstring,$i,1);
  if (is_numeric($char))
    $newstring .= $char;
}

echo "oldstring $oldstring<br>";
echo "newstring $newstring<br>";

exit();

But I need it on mysql, not php

Ah, sorry, things are so much easier to do in php, I didn't even notice you were restricted to MySQL.  Does it HAVE to be in the query?  Is there no way you can use php for this?

No I have to do it on mysql

myyis:

There isn't a way to do it in query using MySQL.  Other databases like Oracle, and SQL-Server, have built-in functions that will do this.

There's a question or two that needs to be answered to best solve this problem:

1) Is this a one-time cleanup, or an ongoing insertion of compromised data into the database.

If it's a one-time-cleanup, then I suggest running a series of update queries to clean up the database.  If it's an on-going insertion of bad data, then I strongly suggest the proper course of action is to address the root cause of the problem.  While this may encounter resistance from some parties, it ALWAYS turns into one maintenance issue after another.  Code must always be added to every query or report to deal with the trash.  This is costly, and violates one of the major best practices regarding databases and their content.

Best regards,

AielloJ

The method that I wrote in the question and the alternative of Aaron Tomosky does the job for me.

What I need to learn is which is faster, nothing more, thank you

The proper way is to store only numbers. write a query to clean what you have and update the database. Then add code to your front end so only numbers get added. That way your output query is fast because it doesn't transform anything.

Thank you Aaron,
I need the format of the numbers, so I don't have chance to get rid of those symbols.

I only want to hear  which method is "theoretically"  faster.
Yours or mine?
Thank you

Even if they are close, mine will handle any format you through at it, so it's much safer. Yours is only replacing specific characters.