IBM Tivoli NetView for z/OS Programming: Pipes - IBM notice

Chapter 6. Using Tivoli NetView for z/OS SQL Stages for
Access to DB2
This chapter describes how to use the Tivoli NetView for z/OS System Query
Language (SQL) stages to access the relational database DB2. Access to SQL is
through pipe stages, enabling you to quickly write powerful systems and network
management applications using REXX, C, PL/I, or other Tivoli NetView for z/OS
supported languages. Also, the SQL and SQLCODE provide compatible language
to similar functions available on VM and MVS/TSO. This simplifies work on
multiple platforms. You can access multiple DB2 databases on the local host.
Accessing and Maintaining Relational Databases (SQL Tables)
Tivoli NetView for z/OS SQL stages can use DB2 if the Tivoli NetView for z/OS
task DSIDB2MT is started and is connected to a DB2 subsystem. Records are
passed between DB2 and the Tivoli NetView for z/OS SQL stage without changing
the format of fields, for example, integers are not printable in a query. This gives
you control over the format of data moving to and from the database. However,
the following sample program SQSELECT, which is supplied with Tivoli NetView
for z/OS SQL stages, formats a query and converts data from internal
representation to character strings:
SQSELECT * from inventory where substr(description,1,4)=’S390’
SUBAREA_NO DESCRIPTION------------- JOBS_ACTIVE
+221 S390 Raleigh NC +2000
+222 S390 Austin TX +1250
The SQL Stage
The SQL stage connects the Tivoli NetView for z/OS program to the relational
database product IBM DATABASE 2 (DB2) for MVS. Potential users of SQL include
the following:
v Novice users of DB2 and Tivoli NetView for z/OS pipelines:
– SQSELECT is a Tivoli NetView for z/OS REXX procedure to format a query
for display.
– Input lines read by a Tivoli NetView for z/OS SQL stage are issued as DB2
statements such as INSERT or SELECT statements. The format of data is the
internal DB2 format; use the EDIT stage to convert between external and
internal formats.
v Tivoli NetView for z/OS SQL stage users who are new to DB2. Advanced DB2
education is outside the scope of this book. See the examples provided and DB2
publications to learn about DB2.
The REXX samples provide program templates, illustrating the major steps to be
performed. Writing SQL applications using Tivoli NetView for z/OS pipelines
eliminates many of the programming details, such as DB2 precompilation,
reentrant considerations, and the details of memory management.
Defining DB2 to the Tivoli NetView for z/OS program
v The DSIDB2DF member of DSIPARM is read when task DSIDB2MT starts, and
defines the DB2 subsystem (SUBSYSTEM=DB2) to which the Tivoli NetView for
z/OS system connects. It uses the following definition statement:
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