title: How does the where clause in MySQL work?
body: <p>I have a doubt. Assume R and S are 2 relations with attributes A and B respectively . If I have a query </p>
  
  <pre><code>Select * 
  From R, S
  Where R.A = S.B 
  </code></pre>
  
  <p>Does this work like a double For Loop in say c or c++ </p>
  
  <pre><code>For( i=0; i&lt;n; i++)
      For( j=0; j&lt;n; j++)
          if (i == j)
             //DO some work 
  </code></pre>