title: How to remove non-numeric characters from MySQL cells
body: <p>I have a table with ~200,000 rows. There are three different phone number columns and the data in them is not all formatted the same. I'd like to remove any value that is not a number and update every cell.</p>
  
  <p>For instance, <code>(412)641-5892</code> becomes <code>4126415892</code>.</p>
  
  <p>I found this STRIP_NON_DIGIT() function <a href="https://stackoverflow.com/questions/287105/mysql-strip-non-numeric-characters-to-compare">here</a>. I can use that in my SQL queries and it works properly, but it takes a minute to return a result. I'd like to run a mass UPDATE across the entire table, but not sure what the syntax is for that.</p>
  
  <p>Something like this is what I'm going for.</p>
  
  <pre><code>UPDATE leads 
  SET phone    = STRIP_NON_DIGIT(phone), 
  mobile_phone = STRIP_NON_DIGIT(mobile_phone), 
  home_phone   = STRIP_NON_DIGIT(home_phone)
  </code></pre>