#1) Data Mapping
In software systems, data often travels back and forth from the UI (user interface) to the backend DB and vice versa. So these are some aspects to watch for:
- Check whether the fields in the UI/frontend forms are mapped consistently with the corresponding fields in the DB table. Typically this mapping information is defined in the requirements documents.
- Whenever a certain action is performed at the front end of an application, a corresponding CRUD (Create, Retrieve, Update and Delete) action gets invoked at the back end. A tester will have to check if the right action is invoked and whether the invoked action in itself is successful or not.
#2) ACID Properties Validation
Atomicity, Consistency, Isolation, and Durability. Every transaction a DB performs has to adhere to these four properties.
- Atomicity means that a transaction either fails or passes. This means that even if a single part of the transaction fails- it means that the entire transaction has failed. Usually, this is called the “all-or-nothing” rule.
- Consistency: A transaction will always result in a valid state of the DB
- Isolation: If there are multiple transactions and they are executed all at once, the result/state of the DB should be the same as if they were executed one after the other.
- Durability: Once a transaction is done and committed, no external factors like power loss or crash should be able to change it
#3) Data Integrity
For any of the CRUD Operations, the updated and most recent values/status of shared data should appear on all the forms and screens. The value should not be updated on one screen and display an older value on another one.
When the application is under execution, the end-user mainly utilizes the ‘CRUD’ operations facilitated by the DB Tool.
C: Create – When user ‘Save’ any new transaction, ‘Create’ operation is performed.
R: Retrieve – When user ‘Search’ or ‘View’ any saved transaction, ‘Retrieve’ operation is performed.
U: Update – When user ‘Edit’ or ‘Modify’ an existing record, the ‘Update’ operation of DB is performed.
D: Delete – When a user ‘Remove’ any record from the system, ‘Delete’ operation of DB is performed.
Any database operation performed by the end-user is always one of the above four.
So devise your DB test cases in a way to include checking the data in all the places it appears to see if it is consistently the same.
#4) Business Rule Conformity
More complexity in Databases means more complicated components like relational constraints, triggers, stored procedures, etc. So testers will have to come up with appropriate SQL queries in order to validate these complex objects.