TOP Database Testing Interview Questions and Answers
How do SQL queries will effect the performance of the application?
Yes, sql queries make a lot of impact on the whole performance of application. A poorly written sql query by a developer can take long time to generate a report or retrieve data from data base. So, we need to take few precautions while writing queries, as a database tester I will also review the queries written by a developer. For example: get rid of nested sql queries as much as possible and make use of joins.
How can you retrieve unique rows from a table?
I can do that by using a DISTINCT keyword in my sql query. eg: select DISTINCT * from products where product_category = ‘Electronics’;
What are the different types of Join conditions in SQL?
Inner join, Outer Join, Left outer join, Right outer join. And try to explain each of them if he gives time.
Provide an example of what can be manually tested in a database.
Non-editable fields through the database can be tested manually. For example, a field that is non-editable through the front end, should not allow a user to add a record to the database.
What is typically checked during database testing?
The following items are typically checked during database testing:
Validation of field size (application matches what resides in database)
Indexes (associated with performance related issues)
How should test cases be written for database testing?
Test cases for database testing should include the following information: project name, module name, bug ID number, test objective, steps/actions, expected results, actual results, status, priority of defect, and severity of defect.
What is used to check data loading during database testing?
Query analyzer can be used to check data loading. 3.
Which SQL statements have you used for testing databases?
This is a basic interview question used to determine your experience with using SQL and databases. Simply provide enough information to adequately display your knowledge of these items.
What we normally check for in the Database Testing?
In DB testing we need to check for,
1. The field size validation
2. Check constraints.
3. Indexes are done or not (for performance related issues)
4. Stored procedures
5. The field size defined in the application is matching with that in the db.