An IN search condition compares expression with the set of values returned by query-expression or the set of values specified in expression-list. Without the NOT keyword, the IN search condition evaluates according to the following rules:
TRUE if expression is not NULL and equals at least one of the values.
UNKNOWN if expression is NULL and the values list is not empty, or if at least one of the values is NULL and expression does not equal any of the other values.
FALSE if expression is NULL and query-expression returns no values; or if expression is not NULL, none of the values are NULL, and expression does not equal any of the values.
The NOT keyword interchanges TRUE and FALSE.
The search condition expressionIN ( expression-list ) is equivalent to expression = ANY ( expression-list ).
The search condition expressionNOT IN (expression-list) is equivalent to expression <> ALL (expression-list ).
The expressions in an expression-list can be a literal, variable, host variable, or a query expression whose result is a single row and a single column.
Syntax