Sequence Operator Sample

About This Sample

This sample uses a Sequence operator to generate unique ID numbers for generic product orders, allowing for easy querying when updating orders. The Orders input stream contains the fields name, productNum, quantity, and price. The OrdersChanges input stream contains the same fields plus an orderID field.

Importing This Sample into StreamBase Studio

In StreamBase Studio, import this sample with the following steps:

  • From the top menu, click FileLoad StreamBase Sample.

  • Type operator to narrow the list of options.

  • Select Operator sample group from the Data Constructs and Operators category.

  • Click OK.

StreamBase Studio creates a single project for all the operator samples.

Running Sequence.sbapp in StreamBase Studio

  1. In the Project Explorer, open the sample you just loaded.

  2. Open the src/main/eventflow folder.

  3. Open the package folder (most samples contain a single package folder. Open the top-level package folder if your sample contains more than one folder).

  4. Open the Sequence.sbapp application and click the Run button. This opens the SB Test/Debug perspective and starts the application.

    If you see red marks, wait a moment for the project in Studio to load its features.

    If red marks do not resolve themselves in a moment, select the project and right-click MavenUpdate Project from the context menu.

  5. In the Manual Input view, select the Orders input stream.

  6. Enter G Washington, 12345678, 1000, and 4.30 in the name, productNum, quantity, and price fields, respectively.

  7. Click Send Data and observe that this order has been assigned a field orderID of 1.

  8. In the Manual Input view, select the OrderChanges input stream.

  9. Enter 1 and 1350 in the orderID and quantity fields, respectively.

  10. In the Application Output view, note that the quantity of the previously entered order has been updated.

  11. Reselect the Orders input stream.

  12. Enter G Washington, 23456789, 900, and 12.50 in the name, productNum, quantity, and price fields, respectively.

  13. Click Send Data and observe that this order has been assigned a field orderID of 2.

  14. Reselect the OrderChanges input stream.

  15. Enter 2, 98765432, and 1900 in the orderID, productNum, and quantity fields, respectively.

  16. Click Send Data and observe that the second order input has been updated.

  17. When done, press F9 or click the Stop Running Application button.

Running Sequence.sbapp in Terminal Windows

This section describes how to run the sample in UNIX terminal windows or Windows command prompt windows. On Windows, be sure to use the StreamBase Command Prompt from the Start menu as described in the Test/Debug Guide, not the default command prompt.

  1. Open terminal windows on UNIX, or four StreamBase Command Prompts on Windows. In each window, navigate to the directory where the sample is installed, or to your workspace copy of the sample, as described above.

  2. In window 1, type:

    sbd Sequence.sbapp

    The window shows notice[StreamBaseServer] listening on port 10000

  3. In window 2: type:

    sbc dequeue OutputOrders

    No output is displayed at this point, but the dequeuer is prepared to receive output. This window will eventually show the output of the application.

  4. In window 3, type:

    sbc enqueue OrderChanges

    The sbc command is now awaiting keyboard input.

  5. In window 4, type:

    sbc enqueue Orders

    The sbc command is now awaiting keyboard input. Then type: G Washington, 12345678, 1200, 4.30

    Observe this line in the dequeue window: G Washington,12345678,1200,4.3,1,null,null,null,null. Notice that this order has been assigned an orderID of 1 in the fifth field. (The null values at the end mean that this is a new order.)

  6. In window 3, type:

    1,null,null,1350,null

    Observe this line in the dequeue window: G Washington,12345678,1350,4.3,1,G Washington,12345678,1200,4.3

    The first set of values are the new order values and the second set of values (that were null before) show the old values.

  7. In window 4, type:

    G Washington, 23456789, 900, 12.50

    Observe this line in the dequeue window: G Washington,23456789,900,12.5,2,null,null,null,null

  8. In window 3, type:

    2, null, 98765432, 1900, null

    Observe this line in the dequeue window: G Washington,98765432,1900,12.5,2,G Washington,23456789,900,12.5

  9. In window 3 and 4 type Ctrl+C to stop the sbc commands.

  10. In window 3 or 4, type the following command to terminate the server and dequeuer:

    sbadmin shutdown

Back to Top ^

Importing This Sample into StreamBase Studio

In StreamBase Studio, import this sample with the following steps:

  • From the top menu, click FileLoad StreamBase Sample.

  • Select operator from the Data Constructs and Operators category.

  • Click OK.

StreamBase Studio creates a single project for all the operator samples.

Sample Location

When you load the sample into StreamBase Studio, Studio copies the sample project's files to your Studio workspace, which is normally part of your home directory, with full access rights.

Important

Load this sample in StreamBase Studio, and thereafter use the Studio workspace copy of the sample to run and test it, even when running from the command prompt.

Using the workspace copy of the sample avoids permission problems. The default workspace location for this sample is:

studio-workspace/sample_operator

See Default Installation Directories for the default location of studio-workspace on your system.