Database testing means test engineer should test the data integrity, data
accessing,query retriving,modifications,updation and deletion etc
Types of testings and processes
Black Box Testing in Database testing
Black box testing involves testing interfaces and the integration of the
database, which includes:
1. Mapping of data
(including metadata)
2. Verifying incoming
data
3. Verifying outgoing
data from query functions
4. Various techniques
such as Cause effect graphing technique, equivalence partitioning and boundary-value analysis.
With the help of these techniques, the functionality of the database can
be tested thoroughly.
Pros and Cons of black box testing include: Test case generation in
black box testing is fairly simple. Their generation is completely independent
of software development and can be done in an early stage of development. As a
consequence, the programmer has better knowledge of how to design the database
application and uses less time for debugging. Cost for development of black box
test cases is lower than development of white box test cases. The major
drawback of black box testing is that it is unknown how much of the program is
being tested. Also, certain errors cannot be detected.
White Box Testing in database testing
White box testing mainly deals with the internal structure of the
database. The specification details are hidden from the user.
1. It involves the
testing of database triggers and logical views which are going to support database refactoring.
2. It performs module
testing of database functions, triggers, views, SQL queries etc.
3. It validates
database tables, data models, database schema etc.
4. It checks rules
of Referential integrity.
5. It selects default
table values to check on database consistency.
6. The techniques used
in white box testing are condition coverage, decision coverage, statement
coverage, cyclomatic complexity.
The main advantage of white box testing in database testing is that
coding error are detected, so internal bugs in the database can be eliminated.
The limitation of white box testing is that SQL statements are not covered.
The WHODATE approach for database testing
While generating test cases for database testing,
the semantics of SQL statement need to be reflected in the test cases. For that
purpose, a technique called WHite bOx Database Application TEchnique
"(WHODATE)" is used. As shown in the figure, SQL statements are
independently converted into GPL statements, followed by traditional white box
testing to generate test cases which include SQL semantics.
Four stages of database testing
- Set Fixture
- Test
run
- Outcome
verification
- Tear
down
A set fixture describes the initial state of the database before
entering the testing. After setting fixtures, database behavior is tested for
defined test cases. Depending on the outcome, test cases are either modified or
kept as is. The "tear down" stage either results in terminating
testing or continuing with other test cases.[5]
For successful database testing the following workflow executed by each
single test is commonly executed:
1. Clean up the
database: If the testable data is already present in the database, the database
needs to be emptied.
2. Set up Fixture: A
tool like PHPUnit will
then iterate over fixtures and do insertions into the database.
3. Run test, Verify
outcome and then Tear down: After resetting the database to empty and listing
the fixtures, the test is run and the output is verified. If the output is as
expected, the tear down process follows, otherwise testing is repeated.
Some problems in database testing
1. The setup for
database testing is costly and complex to maintain because database systems are
constantly changing with expected insert, delete and update operations.
2. Extra overhead is
involved in order to determine the state of the database transactions.
3. After cleaning up
the database, new test cases have to be designed.[citation needed]
4. An SQL generator is
needed to transform SQL statements in order to include the SQL semantic into
database test cases.
http://www.softwaretestinghelp.com/database-testing-process/
http://www.agiledata.org/essays/databaseTesting.html
