SQL/MX Queuing and Publish/Subscribe Services

HP NonStop SQL/MX Queuing and Publish/Subscribe Services—523734-002
3-1
3 Embedded SQL Examples
As described in Section 2, Major Queuing Features, many of the queuing features can
be executed within the SQL/MX conversational interface (MXCI). However, to ensure
use of all the features, the queuing extensions are embedded in a program.
Note that queuing and publish/subscribe services are also supported in Java
applications that contain embedded SQL/MX statements. For examples, see the
SQL/MX Programming Manual for Java.
In the examples in this section, the DECLARE CURSOR statement specifies the WITH
HOLD clause that defines the cursor as a holdable cursor. The cursor remains open
and maintains its position in the result set even though a transaction might terminate
following the fetch operation.
In addition to the WITH HOLD clause of the DECLARE CURSOR statement, this
section provides embedded SQL examples of these features:
The examples in this section use the database in Appendix A, The Shipping Database.
Note that the examples apply to both SQL/MP and SQL/MX tables, as described in
Support for SQL/MP and SQL/MX Tables
on page 1-5.
The routePackage function is assumed to be a function that results in the package
being physically labeled with a bar code indicating the intermediate hub.
Stream Access
on page 3-2 Allows an application to access regular
database tables as continuous data streams.
Embedded DELETE on page 3-3 Allows an application to select and delete rows
in one statement execution.
Embedded UPDATE on page 3-4 Allows an application to select and update
rows in one statement execution.
Skip Conflict Access on page 3-5 Allows an application to skip rows that are
locked by a concurrent transaction.
Set Column Values on Rollback on
page 3-6
Allows an application to update columns when
aborting a transaction during an embedded
DELETE or UPDATE operation.
Rowset Integration on page 3-7 Allows an application to enqueue or dequeue
multiple rows at one time.
Join With a Stream on page 3-8 Allows an application to not materialize the
intermediate result set of a join between a
stream and the inner table of the join.
Managing Transactions With the
Stream Timeout Attribute on
page 3-10
Allows an application to minimize the duration
of transactions while the stream waits.