title: Composite primary keys vs auto increment primary key in sql workbench
body: <p>I need the advice of someone who has a greeter experience.</p>
  <p>I have an associative entity in my database, like that:</p>
  <pre><code>Table2-&gt; CustomerID, ServiceID, DateSub
  </code></pre>
  <p>Since the same customer (with PK, for example 1111) can require the same service (with PK, for example 3) more than once <strong>but never in the same date</strong> , the composite PK of Table 2 can't be just (CustomerID, ServiceID).</p>
  <p>Now I have 2 options:</p>
  <p>1- Also <strong>&quot;DateSub&quot; will be a primary key</strong>, so the PK of table 2 will be (CustomerID, ServiceID, DateSub)</p>
  <p>2- Create a <strong>specific PK</strong> for the associative entity (for example, Table2ID, and so CustomerID and Service ID will be FK)</p>
  <p>Which of the 2 approach would you follow and why? Thank you</p>