title: Change number of decimal digits in all tables in MySQL
body: <p>I'm not much experienced in SQL and I need to modify my tables as follows but cannot work out how to do so.</p>
  
  <p>I have a MySQL database with multiple tables where some of the columns have type e.g. DECIMAL(17, 2) and I need to change the type to have at least 4 decimal places as effectively as possible.</p>
  
  <p>Can someone help me with this please?</p>
  
  <p>Thank you in advance.</p>