This n8n workflow facilitates comparison between two lists of transaction data, typically imported from external sources or triggered by another workflow. It allows users to identify common transactions, those unique to each list, and handles cases where input data might be missing or incomplete. The workflow is designed to work in automation scenarios where data consistency or discrepancies need to be monitored, such as in financial audits or transaction validations.

The workflow begins with an ‘Execute Workflow Trigger’ node that receives two lists (‘input_a’ and ‘input_b’) along with a key to compare on, such as ‘transaction_id’. It then proceeds to a ‘Code’ node that processes the data: it converts the lists into Maps for efficient lookup, compares the items based on the key, and segments the entries into three categories: common, only in A, and only in B.

A ‘Switch’ node is used to check if the required inputs (‘key’, ‘input_a’, ‘input_b’) are provided. If any are missing, specific validation messages are generated, guiding the user to supply the necessary data. When all inputs are valid, the comparison results are outputted, providing a structured set of the common transactions and unique ones for further analysis.

This workflow is particularly useful in environments where data reconciliation from multiple sources is necessary, such as comparing transaction records from two different systems or datasets after data imports, ensuring data integrity and identifying discrepancies quickly and efficiently.