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UDFs callable as void functions

Changed in: 2.0

Description

In Firebird 2.0 and above, PSQL code may call UDFs without assigning the result value, i.e. like a Pascal procedure or C void function. In most cases this is senseless, because the main purpose of almost every UDF is to produce the result value. Some functions however perform a specific task, and if you're not interested in the result value you can now spare yourself the trouble of assigning it to a dummy variable.

Note: RDB$GET_CONTEXT and RDB$SET_CONTEXT, though classified in this guide under internal functions, are actually a kind of auto-declared UDFs. You may therefore call them without catching the result. Of course this only makes sense for RDB$SET_CONTEXT.

See also:
User-defined function (UDF)
External functions
External functions (UDFs)
ALTER EXTERNAL FUNCTION
DECLARE EXTERNAL FUNCTION
DROP EXTERNAL FUNCTION
Passing NULL to UDFs in Firebird 2
Threaded Server and UDFs
How to write an internal UDF function
Firebird Null Guide: NULL <> non-NULL conversions you didn't ask for

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