title: category based queries in mysql
body: <p>I want to write a query in mysql. my scenario is as follow:</p>
  
  <pre><code>Class   Minmarks  MaxMarks
  A         751      1000
  B         501      750
  c         251      500
  D         1        250
  </code></pre>
  
  <p>there are 3 columns: class,minmarks ,maxmarks. If I got 450 marks then what is my class? How to write this in mysql?</p>