SQL: Visual QuickStart Guide

Finding Different Rows with EXCEPT

An EXCEPT operation, also called a difference, combines the results of two queries into a single result that comprises the rows that belong only to the first query. To contrast INTERSECT and EXCEPT, A INTERSECT B contains rows from table A that are duplicated in table B, whereas A EXCEPT B contains rows from table A that aren’t duplicated in table B. Differences have the same restrictions as unions; see “Combining Rows with UNION” earlier in this chapter.

To find different rows:

• Type:

  								select_statement1
  EXCEPT
  select_statement2;
  

  select_statement1 and select_statement2 are SELECT statements. The number and the order of the columns must be identical in both statements, and the data types of corresponding columns ...