Automatic, configurable, and partial assessment of student SQL queries with subqueries

Universities provide database-related courses, where students demonstrate their acquired knowledge by writing SQL code as a solution to presented problems. Manual assessment of students’ solutions lasts for days and brings up additional problems: inconsistency in grading, students waiting long for their grades, and they get clarification feedback with details only on demand. Also, not a negligible number of teachers’ clarification results in correction of initially obtained points. Many authors research the possibility to create computer systems for fully automated assessments, which would minimize or completely annul listed challenges. The authors propose a novel system for automatic, configurable, and partial assessment of student SQL queries. Initially, it supported only basic SELECT statements but was upgraded later to support also complex joins and groupings. The comparison of new system output and teachers’ manual assessments concluded that the novel, fully automated assessment system is very promising. Now, the authors upgraded the assessment model to support subqueries, which are widely used, and thus, an integral part of database courses and assessments. This paper compares the output of the proposed system with the teachers’ manually provided grades, focused on subqueries. The results of this more comprehensive solution remain promising, even with the new features added.