Using switch() to apply multiple tests

Create a new model: Attribute Scripting
Drag the datasource CRM onto this model
From the datasource open the schema browser, find the table SOURCE_BANK_ACCOUNT_TRANS and create a database collector from it
Create a stream from this database collector – remember to use the button in the hover menu so that the stream attributes are automatically configured
Open the help for the switch() function:
- Press the button in the left-hand menu bar of CenterView – a list of all attribute functions available in CenterView will appear
- Double-click on the entry for switch to bring up the help page
Add an attribute to this stream to hold a description of the transaction type:
- Name: TransactionTypeDesc
- Expression: work out the transaction type description from TRANSACTION_TYPE, using a switch() statement, according to the rules below – use the examples in the help for switch() to get started
  TRANSACTION_TYPE
  Description
  1
  "Direct Debit"
  2
  "Standing Order"
  3
  "ePayment"
  4
  "Cheque"
  Any other value
  "Unknown"
Run the stream and check that your translation of transaction type to transaction type description is correct

Using forEach() to handle lists

Create an aggregate stream, with name Bank Account Summary
Add a pipe from the stream you created in the previous exercise (this is probably called SOURCE_BANK_ACCOUNT_TRANS) to Bank Account Summary
Add to the pipe the grouping:
- ACCOUNT_NUM
Drag the attribute ACCOUNT_NUM into Bank Account Summary from either the pipe or the input stream
Add an attribute:
- Name: TotalPosTrans
- Type: Float
- Expression: using a forEach loop, add up the total of all positive transcations, and store it in this attribute
Run Bank Account Summary to test this new attribute
When this is working, update TotalPosTrans to also calculate the total of negative transcations, and the total of all transcations – and hold them in local variables ($variables)
Add two further attributes – TotalNegTrans and TotalTrans - that allow you to store the values of all negative and all transcations that you calculated in TotalPosTrans
Run Bank Account Summary again to test the new attributes