To write test case for database its just like functional testing
1.Objective:Write the objective that you would like to test. e.g. To check the shipment that is loaded thru xml is getting inserted for particular customer.
2.Write the method of input or action that you do. e.g. Load an xml with all data which can be added to a customer.
3.Expected :Input should be viewed in database. e.g. The shipment should be loaded successfully for that customer, also it should be seen in application.4.You can write such type of test cases for any functionality like update, delete etc.