Dealing with unrecognized characters

Each database has its own way of dealing with characters that it cannot recognize. For example, some databases store an unknown character received from a client as a question mark ("?").

As part of the strategy for converting the database, you should decide what you want to do with these characters or other indicators of unrecognized data. You can convert them to another character, review and change each occurrence on a case-by-case basis, or follow some other process.