您通常如何将数据从电子表格导入多个数据库列？

For whatever reason, I have a lot of clients that have existing data that's stored in spreadsheets. Often there are hundreds, if not thousands of items in each spreadsheet, and asking the client to manually enter them through a website (or heaven forbid importing them that way myself) is out of the question. Typically, this data doesn't simply map spreadsheet column to database column. That would be too easy. Often, the data needs to be manipulated before going into the database (data needs to be split by commas, etc) or the data needs to be spread out across multiple tables. Or both.For whatever reason, I have a lot of clients th