title: MySQL - Change date string to date type in place?
body: <p>(Hi all. I'm new-ish to SQL and MySQL in particular. I know some PHP.)</p>
  
  <p>I have a table which contains a "date_string" column. For legacy reasons, this is a text field, containing the date in d/m/YY format.  e.g. "22/11/09" for 22nd November 2009.</p>
  
  <p>Question: how could I convert all fields in this column to a standard MySQL date format (YYYY-mm-dd), in-place?</p>
  
  <p>Or, failing being able to change it in place, given that the column type is text, how could I take each existing text-based date, and create a standard date in another column (of type 'date') within the table?</p>
  
  <p>Thanks for any help.</p>