Interface from HR to Payroll Software

A client upgraded their HR system and had a requirement to create a changes only export file. This was based on the audit trail within their new HR system.  The changes only export file, needed to extract from the HR software data relevant and required to the Payroll software.The business driver was to avoid the need for dual entry of data into both systems. Thus improving the efficiency of the team, and also the accuracy of the data.We ascertained the required fields needed by the Payroll software. Then we wrote a SQL script that could be supplied with date parameters, and also run on demand.  This data was then written to a CSV file and downloaded.