September 2007
Intermediate to advanced
672 pages
13h 23m
English
You now know two ways to filter your final result set: WHERE and HAVING. You also know that there are certain limitations on the predicates you can use within a search condition in a HAVING clause. In some cases, however, you have the choice of placing a predicate in either clause. Let’s take a look at the reasons for putting your filter in the WHERE clause instead of the HAVING clause.
You learned in Chapter 6 about five major types of predicates you can build to filter the rows returned by the FROM clause of your request. These are comparison (=, <>, <, >, >=, <=), range (BETWEEN), set membership (IN), pattern match (LIKE), and Null (IS NULL). In Chapter 11, we expanded ...