Database Testing

Database is the core and critical part of almost every software application. So DB testing of an application demands keen attention, good SQL skills, proper knowledge of DB structure of AUT and proper training.

1. Create your own Queries

In order to test the DB properly and accurately, first of all a tester should have very good knowledge of SQL and specially DML (Data Manipulation Language) statements. Secondly, the tester should acquire good understanding of internal DB structure of AUT. If these two pre-requisites are fulfilled, then the tester is ready to test DB with complete confidence. (S)He will perform any CRUD operation from the UI of application, and will verify the result using SQL query.

This is the best and robust way of DB testing especially for applications with small to medium level of complexity. Yet, the two pre-requisites described are necessary. Otherwise, this way of DB testing cannot be adopted by the tester.

Moreover, if the application is very complex then it may be hard or impossible for the tester to write all of the needed SQL queries himself or herself. However, for some complex queries, tester may get help from the developer too. I always recommend this method for the testers because it does not only give them the confidence on the testing they have performed but, also enhance their SQL skill.

2. Observe data table by table

If the tester is not good in SQL, then he or she may verify the result of CRUD operation, performed using GUI of the application, by viewing the tables (relations) of DB. Yet, this way may be a bit tedious and cumbersome especially when the DB and tables have large amount of data.

Similarly, this way of DB testing may be extremely difficult for tester if the data to be verified belongs to multiple tables. This way of DB testing also requires at least good knowledge of Table structure of AUT.

3. Get query from developer

This is the simplest way for the tester to test the DB. Perform any CRUD operation from GUI and verify its impacts by executing the respective SQL query obtained from the developer. It requires neither good knowledge of SQL nor good knowledge of application’s DB structure.

So, this method seems easy and good choice for testing DB. But, its drawback is havoc. What if the query given by the developer is semantically wrong or does not fulfill the user’s requirement correctly? In this situation, the client will report the issue and will demand its fix as the best case. While, the worst case is that client may refuse to accept the application.