If you specify the NOT operator, the IN condition is TRUE when
the expression is not in the list of items. NULL values do not satisfy
the IN condition.
The following examples show some IN conditions:
WHERE state IN ('CA', 'WA', 'OR')
WHERE manu_code IN ('HRO', 'HSK')
WHERE user_id NOT IN (USER)
WHERE order_date NOT IN (TODAY)
In ,
the built-in TODAY function is evaluated at execution time. The built-in
CURRENT function is evaluated when a cursor opens or when the query
executes, if it is a singleton SELECT statement.
The built-in USER function is case sensitive; for example, it interprets minnie and Minnie as
different values.