title: For all strings s1 in table change all substrings s2 to substrings s3
body: <p>There is a table <code>t1(id int, string1 varchar(15), string2 varchar(15), string3 varchar(15))</code>. How can I write a request that returns a table <code>(id int, res1 varchar(200))</code> in which res1 is s1 in which all entries of substring s2 changed to substring s3?</p>
  
  <p>For example if t1 contains 2 strings:
  <code>(0, 'catcat', 'cat',  'dog')
  (1, 'dddod', 'd', 'a')</code> result should be a table
  <code>(0, 'dogdog')
  (1, 'aaaoa')</code></p>