As we saw in the last article, the SQL SELECT statement has the widest variety of query options, ... MIN—A function that returns the lowest non-null value in a column; ...

To test for the existence of nulls, use the special predicate IS NULL in the WHERE clause of the SELECT statement. You cannot simply state WHERE column = NULL. You must state WHERE column IS NULL, for ...

You can use the SQL procedure's SELECT statement to display data that is described by a view descriptor. In the following example, the query uses the VLIB.PRODUCT view descriptor to retrieve a subset ...