Creating the database for practice? There are inexpensive personal finance applications, depending on your platform.
This is a list of FMP Links I consider useful. http://forums.filemaker.com/posts/39ab6dcf1c?commentId=217671#217671
This is a free but not open for modification database.
The Excelisys Business Tracker V3.0 -
If you use one table set up as a transactions ledger (Think in terms of how you would set up a check register on paper), you can add a field that identifies the credit card account. Then you can perform a find to find all records for a specified account, or you can sort your records by this field to group them by account. You can define a running total summary field that gives you the current total charges and/or total balance on each account and that restarts the running total with each group of account transactions when you sort by that field.