HP NonStop SQL/MP Programming Manual for C—429847-008
D-1
D
Converting C Programs
A C program developed for NonStop SQL/MP version 1 or version 2 software can run
on SQL/MP version 300 (or later) software without any changes to its embedded SQL
statements or directives. However, to use new SQL features, you must modify and
recompile the program.
Topics include:
Generating SQL Data Structures
Generating SQLDA Structures
on page D-2
Planning for Future PVUs
on page D-8
Generating SQL Data Structures
The SQLCA, SQLSA, and SQLDA data structures can change in future PVUs of
NonStop SQL/MP. Follow these guidelines if you are converting an existing C program
(that is, a program that uses version 1 or version 2 structures) or writing a new
program to use version 300 (or later) SQL structures:
Use the INCLUDE STRUCTURES directive to specify the version of the SQL
structures, even if you require version 1 or version 2 structures. To generate
version 300 or later structures, you must use the INCLUDE STRUCTURES
directive. For more information, see
Section 9, Error and Status Reporting
.
If you allocate SQL data structures at run time, use the compiler-generated length
identifiers (for example, SQLSA_LEN for the length of an SQLSA structure) to
specify the memory to allocate. (In some cases, you can also use a C function to
generate the length of a structure.) Using the compiler-generated length identifiers
can reduce the impact on a program if the size of an SQL data structure changes
in a future PVU.
Use the system-generated eye-catcher identifiers to initialize the eye-catcher
fields. Do not hard code eye-catcher values or write code that depends on
hard-coded values. The eye-catcher values can change in a new PVU.
Use the SQLCAGETINFOLIST procedure to return information from the SQLCA
structure. Do not access this structure directly. HP reserves the right to change the
SQLCA structure in future PVUs.
Note.
A D20 (or later) C compiler requires that a C program comply to the ISO/ANSI C
standard. For information about converting a program to follow this standard, see the
C/C++
Programmer’s Guide
.
Also, a C-series program can run at a low PIN on a D-series system without any changes.
However, for a C-series program to use D-series features (for example, to run at a high PIN),
you might need to convert certain parts of the program. For information about converting a
C-series program to use D-series features, see the
Guardian Application Conversion Guide
.
Summary of Contents for NonStop SQL/MP
Page 4: ......
Page 14: ...Contents HP NonStop SQL MP Programming Manual for C 429847 008 x ...
Page 60: ...Host Variables HP NonStop SQL MP Programming Manual for C 429847 008 2 26 VARCHAR Data Type ...
Page 294: ...SQL MP Sample Database HP NonStop SQL MP Programming Manual for C 429847 008 A 6 ...