SQL/MX Programming Manual for C and COBOL (G06.24+, H06.03+)

Transaction Management
HP NonStop SQL/MX Programming Manual for C and COBOL—523627-004
14-3
Declaring Required Variables
For more information, see:
1. Declaring Required Variables on page 14-3
2. Setting Attributes for Transactions on page 14-3
3. Starting a Transaction on page 14-6
4. Processing Database Changes on page 14-7
5. Testing for Errors on page 14-7
6. Committing Database Changes if No Errors Occur on page 14-8
7. Undoing Database Changes if an Error Occurs on page 14-8
Declaring Required Variables
Declare SQLSTATE and host variables you need within your program.
Examples
char SQLSTATE_OK[6] = "00000";
EXEC SQL BEGIN DECLARE SECTION;
char SQLSTATE[6];
...
EXEC SQL END DECLARE SECTION;
01 SQLSTATE-OK PIC X(5) VALUE "00000".
EXEC SQL BEGIN DECLARE SECTION END-EXEC.
01 SQLSTATE PIC X(5).
...
EXEC SQL END DECLARE SECTION END-EXEC.
Setting Attributes for Transactions
Use a SET TRANSACTION statement to set some of the attributes for subsequent
transactions. When coding a SET TRANSACTION statement in an embedded SQL
program, consider that special considerations exist for setting the isolation level. See
Isolation Level Setting on page 14-5.
* Test if database change is ok.
IF SQLSTATE = SQLSTATE-OK
...
* Commit database change.
EXEC SQL COMMIT WORK END-EXEC.
ELSE
...
* Roll back database change.
EXEC SQL ROLLBACK WORK END-EXEC.
END-IF.
...
Figure 14-2. Coding Transaction Control Statements in a COBOL Program
COBOL
5
6
7
C
COBOL