Publicly available SQL sample data

If there are any publicly available sample date to learn SQL, please let me know. Especially, the data used in business activity such as financial (general ledger, sub ledger, income statement, cash flow statement), HR data ( employee, salary etc) and so on.  I'm trying to create dummy data to learn queries but it takes time and cannot make large data.. It's appreciate if I can know how people generate data similar to real data for practice.