NOTE: SQL Query

You are working on a billing application and need to get a list of customers with their transaction transcripts.

The result should have the following columns: iban / transactions / total.

• iban - client's IBAN number
• transactions - list of transaction amount records for a specific IBAN:
  • Record a transaction amount
  • Records are separated by the sign of the amount of the transaction surrounded by a single space. See 'Expected Output' for an example.
  • Records are sorted in ascending order of dt
• total - the total amount of all transactions for a specific IBAN

The result should be sorted in descending order by total.

Schema: