Class Database uses ADO API. It works with many databases, and each can have own SQL dialect. I don't know what SQL is used for CSV files.
https://www.google.com/search?q=ADO+CSV+SQL+dialect
CsText uses this code to create the connection string:
Member function Database.CsText
https://www.google.com/search?q=ADO+CSV+SQL+dialect
CsText uses this code to create the connection string:
Member function Database.CsText