“There is no ambiguity on what to return”: Investigating the Prevalence of SQL Misconceptions

In recent years, database education has been receiving more attention, with research in various directions such as the development of tools for education, the analysis of students’ homework, and the exploration of misconceptions. Misconceptions are mistakes in student reasoning that lead to errors during problem-solving. Recent work has documented misconceptions and errors in SQL. In this study we test the prevalence of several of these misconceptions through a multiple-choice questionnaire, to see if they hold on a larger, more diverse, student population. We found that all misconceptions are held to some extent, with prevalence scores ranging from one to fifty-two percent of the student population. Additionally, we have uncovered previously unidentified areas of struggle, allowing us to identify new misconceptions.