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
14-2
Steps for Ensuring Data Consistency
Figure 14-2 shows the steps presented within the complete COBOL program. These
steps are executed in the sample program Example C-2 on page C-4.
/* Set attributes for the transaction. */
EXEC SQL SET TRANSACTION
READ WRITE,
ISOLATION LEVEL SERIALIZABLE,
DIAGNOSTICS SIZE 10;
...
EXEC SQL BEGIN WORK; /* Begin the transaction. */
...
EXEC SQL UPDATE ... ; /* Process database changes. */
...
if (strcmp(SQLSTATE, SQLSTATE_OK) == 0) { /* Test if OK. */
...
...
EXEC SQL COMMIT WORK; /* Commit database changes. */
}
else {
...
EXEC SQL ROLLBACK WORK; /* Rollback database changes. */
}
...
Figure 14-2. Coding Transaction Control Statements in a COBOL Program
...
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.
...
* Set attributes for the transaction.
EXEC SQL SET TRANSACTION
READ WRITE,
ISOLATION LEVEL SERIALIZABLE,
DIAGNOSTICS SIZE 10
END-EXEC.
...
* Begin the transaction.
EXEC SQL BEGIN WORK END-EXEC.
...
* Process database changes.
EXEC SQL UPDATE ... END-EXEC.
...
Figure 14-1. Coding Transaction Control Statements in a C Program
C
2
3
4
5
6
7
COBOL
1
2
3
4