By the end of this chapter you will be able to:
Use an output multiplier to break out a record into multiple output records
In this exercise you will load reference data into your model which lists all the TV channels offered in each package. You will use this to break out each customer record, in Latest Package Update
, into a set of records for each channel that the customer has ordered.
Load data from a database table
In this section you will load the database table SOURCE_PACKAGE_CHANNELS
into a stream. Your model will then have the full list of channels available in each package.
Remember, the Introduction to Modelling course explains about loading data from databases; see section 3 Creating Datasources and Database Collectors.
- In the repository browser, expand the list of Datasources.
- Drag the datasource called
Rating and Billing
into your model. - In your model, hover your mouse pointer over
Rating and Billing
and clickError rendering macro 'excerpt-include' : No link could be created for '_show_tables'.. PhixFlow displays a list of the tables available in this database. You can resize the list to make it easier to browse. - Right-click on
SOURCE_PACKAGE_CHANNELS
and selectError rendering macro 'excerpt-include' : No link could be created for '_create_collector'.. PhixFlow adds a new database collector to the model, and gives it the same name as the source data table,SOURCE_PACKAGE_CHANNELS
. In the settings → Basic Settings section → Statement Expression, you can see the database query is: select * from SOURCE_PACKAGE_CHANNELS
. - Hover your mouse pointer over the new database collector, and click Error rendering macro 'excerpt-include' : No link could be created for '_add_stream_with_attributes'.. PhixFlow adds a new stream to your model and also gives it the name
. In the settings → Attributes section, you can see that data has two attributes (columns): Package and Channel.SOURCE_PACKAGE_CHANNELS
To load the data into the stream, run analysis on this section of the model and check the data has loaded.
Snapshot of your model and the data you have loaded:
Create a stream for full channel list
Update your model to add a stream. This stream will hold the full channel list.
- Hover your mouse pointer over the
Latest Package Update
stream and clickError rendering macro 'excerpt-include' : No link could be created for '_add_stream'.. - In Basic Settings, set the Name to
Latest Package All Channels
. Drag all the attributes from
Latest Package Update
to the settings forLatest Package All Channels
.- Click Apply and Close to save your changes and close the settings.
- Close the attributes list.
Look up
supplement the Latest Package All Channels stream with additional data from the database, using a lookup pipe.
- In the model, add a pipe from
SOURCE_PACKAGE_CHANNELS
toLatest Package All Channels
. PhixFlow opens the settings for the new pipe. - In Basic Settings section, set:
- Name:
chan
- Type: Look-up
- Name:
- In the Order/Index section, click Error rendering macro 'excerpt-include' : No link could be created for '_stream_attributes'.. PhixFlow opens the list of attributes available from the input stream, in this case
PACKAGE
andCHANNEL
. - Drag
PACKAGE
into the Order/Index section, then double-click the the new line created. PhixFlow opens the settings for the attribute. Set:- Basic Settings → Index Expression from
_out.Package
to:in.Package
.
Technical issue: I'm not seeing _out.Package here. - Click Apply and Close to save and close the attribute settings.
- Basic Settings → Index Expression from
- Close the attribute list.
- In the pipe settings, click Apply and Close to save your changes and close the settings.
This means that the lookup will match records in the reference data (SOURCE_PACKAGE_CHANNELS
) where PACKAGE
= Package
from the input pipe in
We must do this, rather than using the value of Package
from the output because we are using the lookup to drive an output multiplier – and output multipliers are calculated before the output is generated
- Open the configuration form for the stream
Latest Package All Channels
by double clicking it - In the field Output Multiplier, enter the value:
chan.CHANNEL
This means that for each output record processed, PhixFlow will look up the list of channels for the package from the reference stream; it will then work through the list returned, handling each element from the list in turn and generating an output record in the stream for each one
- Add an attribute to the stream with Name
Channel
- Set the Expression of this attribute to
_outputMultiplier
This will print the value of the current element of the output multiplier list to this field
On older models in PhixFlow you may see the internal variable _type. This is the old name for _outputMultiplier. Either can be used, and anywhere you see _type you can update it to _outputMultiplier for clarity. |
- Save your changes
- Run analysis on the stream
Latest Package All Channels
- Check that your output is a full list of all channels for each customer