Getting Started with IBM Data Studio for DB2

Chapter 9– Developing user-defined functions 277
5. To run the UDF again, follow the steps highlighted in Section 9.4. However, since the
updated UDF expects an input parameter, you must specify that parameter. The Run
and Performance Options tab opens in the UDF editor view, where you can specify
whether to commit the changes to the database.
6. Specify the input parameter value, as shown in Figure 9.13, then click OK to run the
UDF.
Figure 9.13 – Specify a value for the input parameter of the UDF
7. As explained in Section 9.5, the status of running the UDF, and any returned value can
be observed in SQL Results view. In this case, the returned value will be a scalar
integer value which is the number of tables inGOSALESCT schema that starts with the
phraseCUST.
9.7 Summary
In this chapter, you learned the value of using user-defined functions to improve
performance of SQL access by being able to process a set of SQL on the database server
rather than sending each request over the wire separately. In addition, by encapsulating
the database logic, those UDFs can be called and used by multiple applications. UDFs also
provide a way to extend the SQL language with your own functions. You also learned the
most important steps in the creation and maintenance of user-defined functions using Data
Studio.
9.8 Exercise
As an exercise for this chapter, create a table UDF that returns the name and schema of all
functions that have the qualifier equal to the value passed as a parameter to the function.