title: How do I search datas in different database tables?
body: <p>I want to search datas in different database tables?</p>
  
  <p>For example, I input a word like 'demo', onclick 'search' button, and than show the datas relate to the 'demo' word from 'product' table and 'article' table.</p>
  
  <p>So, how do I write sql statement?</p>
  
  <p>By the way, I use PHP and Mysql.</p>