title: Get the maximum field value between different tables and the table from which it came
body: <p>I have many tables, say T1, T2, T3. </p>
  
  <p>Every table has a column named <code>field</code>. I'd like to get the maximum value of <code>field</code> in the three tables, but also from which table it came, for example:</p>
  
  <pre><code>T1 { 6, 8, 23 }
  T2 { 8, 45, 23 }
  T3 { 68, 5, 67 }
  </code></pre>
  
  <p>I have to get 68 knowing that it belongs to table T3. I use MySQL as DBMS.</p>