title: SQL Server 2000: "subquery returned more than one value" on an update statement
body: <p>I'm trying to do a simple update. I've done this kind of thing thousands of times. </p>
  
  <pre><code>update articles
  set department = 60
  where type = 'Top Story'
  </code></pre>
  
  <p>Today I get a strange error.</p>
  
  <blockquote>
    <p>Describe Error: Failed to retrieve
    execution plan: Subquery returned more
    than 1 value. This is not permitted
    when the subquery follows =, !=, &lt;, &lt;=
    , >, >= or when the subquery is used
    as an expression.</p>
    
    <p>Warnings: --->     W (1): The
    statement has been terminated.
              &lt;--- </p>
    
    <p>1559 record(s) affected</p>
  </blockquote>
  
  <p>There is no subquery in the update statement. What's going on?</p>