Challenges and Perils of Testing Database Manipulation Code

Software testing enable development teams to maintain thequality of a software system while it evolves. The database manipu-lation code requires special attention in this context. However, it isoften neglected and suffers from software maintenance problems. In thispaper, we investigate the current state-of-the-practice in testing databasemanipulation code. We first analyse the code of 72 projects mined fromLibraries.io to get an impression of the test coverage for database code.We confirm that the database is poorly tested: 46% of the projects didnot cover with tests half of their database access methods, and 33%of the projects did not cover the database code at all. To understandthe difficulties in testing database code, we analysed 532 questions onStackExchange sites and deduced a taxonomy. We found that developersmostly look for insights on general best practices to test database accesscode. They also have more technical questions related to DB handling,mocking, parallelisation or framework/tool usage. This investigation laysthe basis for future research on improving database code testing