title: update column table with value of column from table b if it contains substring from another column from table b
body: <p>There are 2 table like below:</p>
  
  <pre><code>Table a                        Table b
  
  country_name                   id | string_bone   | country_name
  ------------------------       ---+---------------+---------------
  usa                            1  | usa           | united states  
  u s a                          2  | u s a         | united states
  united states of america       3  | america       | united states
  america                        4  | ...           | ...
  </code></pre>
  
  <p>I need to update <code>table_a.country_name</code> with <code>table_b.country_name</code> if <code>table_b.string_bone</code> is contained in <code>table_a.country_name</code>. </p>
  
  <p>I tried this:</p>
  
  <pre><code>UPDATE table_a a
  SET country_name = b.country_name
  WHERE EXISTS (SELECT country_name
                FROM table_b
                WHERE a.country_name LIKE '%' || string_bone || '%') b;
  </code></pre>
  
  <p>I would like <code>table_a</code> to look like this after the update:</p>
  
  <pre><code>Table a                        
  
  country_name                   
  ------------------------       
  united states                            
  united states                          
  united states      
  united states                        
  </code></pre>
  
  <p><a href="https://dbfiddle.uk/?rdbms=postgres_9.5&amp;fiddle=01079ca8b2a4ea222a5b27280f4aeea2" rel="nofollow noreferrer">Here</a> the dbfiddle link.</p>