title: How to set (combine) two primary keys in a table
body: <p>For a small sales related application, we designed database using logical data model. Come  to the stage to convert in to physical model. While creating table in SQL Server Management Studio Express, according to our logical data model, we need to combine two attributes to form unique id. Is it possible to combine two primary keys and set it?</p>
  
  <p>But while observing Northwind Sample, we found that in the <code>ORDER DETAILS</code> table, we can see two primary keys <code>Order Id</code> &amp; <code>Product Id</code>. And according to rule table can't have two primary keys. So how it happened in Northwind? </p>
  
  <p>In my case how should I set two columns in my table to make it as two primary keys?</p>
  
  <p>Someone gave suggestion like </p>
  
  <blockquote>
    <p><em>To make a two primary key, open the table in design view and click
    on the two of the required fields and holding CTL, apply primary key</em></p>
  </blockquote>
  
  <p>Will this work ??</p>
  
  <p>Edit ;</p>
  
  <p>now my table have 2 PK's in the SSMS . is it valid or it is just a combinationof 2 pks<img src="https://i.stack.imgur.com/F8Urd.png" alt="enter image description here"></p>