70
Correlated Queries
 SELECT DISTINCT title
 FROM   Movie AS x
 WHERE  year <> ANY 
                             (SELECT  year
                               FROM    Movie
                               WHERE  title =  x.title);
    Movie (title,  year,  director, length)
    Find movies whose title appears more than once.
Note (1) scope of variables (2) this can still be expressed as single SFW
correlation