Your first option should probably be Bulk Copy, which you can do in SSMS with no .NET development at all. If you want to write .NET code to do it, Bulk Copy is implemented using the SqlBulkCopy class. That would require reading the file into a DataTable, which can be done in a variety of ways, including dedicated third-party libraries. You should do a bit of research for yourself, have a go at implementing it and then let us know if and when you encounter a specific issue.