title: What is collation_database, collation_connection, collation_server used for in MySQL?
body: <pre><code>Illegal mix of collations (big5_chinese_ci,IMPLICIT) and (utf8_general_ci,COERCIBLE) for operation 'like'
  </code></pre>
  
  <p>Sometimes this error is throw, what's up?
  What's the <code>collation_*</code> used for?
  Can someone give me an example to show how the character is encoded, transited and selected, relate to <code>collation_*</code>?</p>