title: Issues with adding foreign key constraint in SQL Server?
body: <p>I am using SQL Server, and I need to add a foreign key to an already existing table.</p>
  
  <p>The issue is the column which will act as the foreign key already has a few inconsistent values (which do not occur as a primary key) in another table.</p>
  
  <p>I was wondering, when I alter the table and add the foreign key constraint, what will happen to the rows in the table with foreign key constraint , which has inconsistent values??</p>
  
  <p>--Neeraj</p>