SQL/MX Queuing and Publish/Subscribe Services

Embedded SQL Examples
HP NonStop SQL/MX Queuing and Publish/Subscribe Services—523734-002
3-9
Join With a Stream
This program illustrates an embedded DELETE accessing a table as a stream, joined
to a regular table:
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#include <stdio.h>
#include <string.h>
long EmbeddedDelete()
{
EXEC SQL BEGIN DECLARE SECTION;
int destination;
int origin;
int seqnbr;
int hub;
long SQLCODE;
EXEC SQL END DECLARE SECTION;
EXEC SQL WHENEVER SQLERROR GOTO EndOfProcessing;
/* Route incoming parcels to next destination */
EXEC SQL DECLARE arrivals CURSOR FOR
SELECT inbox.destination, inbox.origin,
inbox.seqnbr, routes.hub
FROM (DELETE FROM STREAM(inbox)) AS inbox, routes
WHERE inbox.destination = routes.destination
AND inbox.origin = routes.origin;
EXEC SQL CONTROL QUERY DEFAULT materialize reset;
EXEC SQL OPEN arrivals;
/* Wait for newly arrived parcels and notify receivers */
while (1) {
/* Wait for notifications */
EXEC SQL FETCH arrivals
INTO :destination,:origin,:seqnbr,:hub;
printf("\nDestination:%d Origin:%d "
"Sequence number:%d Hub:%d",
destination, origin, seqnbr, hub);
/* Route package to intermediate hub */
routePackage(seqnbr, hub);
}
EndOfProcessing:
EXEC SQL WHENEVER SQLERROR GOTO EndError;
EXEC SQL CLOSE arrivals;
EndError:
return SQLCODE;
}
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