title: SQL UPDATE statement to update a table with values from another table with no unique identifer
body: <p>I have one table that has a non unique identifier and I need to update a corresponding column with a value from another table with a unique identifer.  </p>
  
  <p>Essentially I have two tables</p>
  
  <p>Table1</p>
  
  <pre><code>| Col1 | Col2 |
  ---------------
  |  A   |  1   |
  ---------------
  |  A   |  2   |
  ---------------
  |  B   |  4   |
  ---------------
  |  C   |  6   |
  ---------------
  |  C   |  9   |
  ---------------
  </code></pre>
  
  <p>Table2 </p>
  
  <pre><code>| Col1 | Col2 |
  ---------------
  |  A   |  1   |
  ---------------
  |  B   |  2   |
  ---------------
  |  C   |  3   |
  ---------------
  </code></pre>
  
  <p>I want to perform a calculation on Table1.Col2 with the corresponding values from Table2.Col2 where Table1.Col1 = Table2.Col1 using MySQL.</p>
  
  <p>For Example:</p>
  
  <pre><code>| Col1 | Col2 |
  ---------------
  |  A   |  1   | // (1/1)
  ---------------
  |  A   |  2   | // (2/1)
  ---------------
  |  B   |  2   | // (4/2)
  ---------------
  |  C   |  2   | // (6/3)
  ---------------
  |  C   |  3   | // (9/3)
  ---------------
  </code></pre>
  
  <p>Any help would be appreciated. </p>