Using INVOKE

The INVOKE clause can be used:

·	Independently.

·	In a nested manner, in association with another INVOKE clause.

·	In association with a SELECT clause.

·	In the out-list of a SELECT statement

·	In subqueries

The syntax of the independent INVOKE clause is:

INVOKE <component>.{<method>|<protocol>}

The syntax of the nested INVOKE clause is:

INVOKE <component>.{<method>|<protocol>}

WITH

INVOKE <component>.{<method>|<protocol>}

[WITH ...]

The syntax of the INVOKE ... WITH SELECT construct is:

INVOKE <component>.{<method>|<protocol>}

WITH

SELECT <column>[,<column>...]

FROM <table>[,<table>...]

[WHERE <condition>]

The WITH clause is optional. If there is no WITH clause, the method is called without input parameters. You can also call the method with a constant rather than a queried database value:

INVOKE <component>.<method> WITH SELECT <constant>