Example: A 19   User defined functions to map LEAST

   DB2 UDB UDF(User Defined Function) Samples for Migration

   2001/08/28, 08/29

   Name of UDF: LEAST (P1 VarChar(254), P2 VarChar(254))

   Used UDF: None

   Description: Returns least value of list of data.

   Author: TOKUNAGA, Takashi

CREATE FUNCTION LEAST (P1 VarChar(254), P2 VarChar(254))

 RETURNS VarChar(254)

 LANGUAGE SQL

 SPECIFIC LEASTOracle2

 DETERMINISTIC

 CONTAINS SQL

 NO EXTERNAL ACTION

 RETURN 

CASE

WHEN P1 <= P2 THEN P1

ELSE               P2

END

;

   LEAST function with three parameters

CREATE FUNCTION LEAST (P1 VarChar(254), P2 VarChar(254), P3 VarChar(254))

 RETURNS VarChar(254)

 LANGUAGE SQL

 SPECIFIC LEASTOracle3

 DETERMINISTIC

 CONTAINS SQL

 NO EXTERNAL ACTION

 RETURN 

CASE

WHEN P1 <= P2

THEN CASE

     WHEN P1 <= P3 THEN P1

     ELSE               P3

     END

ELSE CASE

354 

MySQL to DB2 UDB Conversion Guide