Starting the pipeline
With the setup chores taken care of, you can now start the
execution of your pipeline.
To start pipeline execution:
-
Code
the Start function in an appropriate script.
In this function, you specify:-
The Transaction object
for the source database -
The Transaction object for the destination database
-
The DataWindow control in which you want the Start function
to display any error rowsThe Start function automatically associates
the PowerBuilder pipeline-error DataWindow object with your DataWindow
control when needed. -
Values for retrieval arguments you have defined
in the Pipeline objectIf you omit these values, the Start function
prompts the user for them automatically at runtime.
-
-
Test the result of the Start function.
For more information on coding the Start function,
see the PowerScript Reference.
Example
The following sample code starts pipeline execution in the
order entry application.
Calling the Start function
When users want to start their selected pipeline, they click
the cb_write CommandButton in the w_sales_extract window:
This executes the Clicked event of cb_write,
which contains the Start function:
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// Now start piping. |
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integer li_start_result |
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li_start_result = iuo_pipe_logistics.Start & |
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   (itrans_source,itrans_destination,dw_pipe_errors) |
Notice that the user did not supply a value for the pipeline’s
retrieval argument (quarter). As a consequence,
the Start function prompts the user for it:
Testing the result
The next few lines of code in the Clicked event of cb_write check
the Start function’s return value. This
lets the application know whether it succeeded or not (and if not,
what went wrong):
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CHOOSE CASE li_start_result |
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   CASE -3 |
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   Beep (1) |
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   MessageBox("Piping Error", & |
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      "Quarterly_Extract table already exists ... |
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   RETURN |
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   CASE -4 |
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   Beep (1) |
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   MessageBox("Piping Error", & |
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      "Quarterly_Extract table does not exist ... |
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   RETURN |
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   ... |
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END CHOOSE |