title: Join data from two tables without unique key
body: <p>I have two tables in one database (access file).</p>
  
  <p><strong>Table 1</strong>:</p>
  
  <pre><code>| Product Id |  Year     | Sales |
  ----------------------------------
  | 1144       |  2013     | 100   |
  | 20131120   |  2013     | 200   |
  | 1144       |  2012     | 333   |
  </code></pre>
  
  <p><strong>Table 2</strong>:</p>
  
  <pre><code>| Product Id     |  Category     |
  ----------------------------------
  | 1144           | Car           |
  | 20131120       | Motorbike     |
  </code></pre>
  
  <p>The first table (table 1) is the table when user can add new data whenever wants, and the second table is updated once in a while, when new product id appears. I would like to join this table, some kind of relation on the base of Product Id, but I'm not able to use relation due to the lack of unique, primary key, am I right? When I execute SQL query ( <code>SELECT * FROM Table 1</code>) I would like to get the result like this one:</p>
  
  <pre><code>| Product Id |  Year     | Sales | Category   |
  -----------------------------------------------
  | 1144       |  2013     | 100   | Car        |
  | 20131120   |  2013     | 200   | Motrobike  |
  | 1144       |  2012     | 333   | Car        |
  </code></pre>
  
  <p>I know I can join this two tables, but I would like not to do it every time when user add new data to table 1. Do you know any solution how could I do that?</p>