You can move your database to another account
If you want to move your project to another account you need to open your Projects page.
Open context menu and click on "Move" link.
On the next page you need to enter Account ID, that will receive the project.
You can find Account ID on the Account page, "Others" tab:
Please note: when you move a project to another account, the project's export log is moved too (export log belongs to the project). It can affect the account limits.
You can view the export log on the "Account" menu, "Payment and Statistics" page.