Sql Judge: Design and Implementation of an Automated Sql Query Grading Platform for High School Informatics Education
Year: 2026
Type: article
Abstract: This paper presents Structured Query Language (SQL) Judge, a web-based automated SQL grading platform designed for high school informatics education. The study follows a design-and-evaluation methodology consisting of problem analysis, system design, implementation, and pilot evaluation. The main contribution is not a new theory of SQL equivalence, but an integrated engineering solution that combines result-based grading, multi-layer sandboxing, workspace isolation, and teacher-oriented management with configurable SQL-construct requirements in a lightweight platform suitable for school-level deployment. Initial experiments were conducted in a controlled local school-network pilot deployment involving 62 users, 43 SQL questions, and 486 student submissions. The results show that SQL Judge successfully supported query submission, controlled execution, result-based grading, and immediate feedback delivery. The system maintained an average end-to-end response time of 1.42 seconds per submission, with 95% of submissions processed within 4.7 seconds. For complex queries, the average response time was 2.83 seconds, with 95% completed within 6.5 seconds. In addition, the sandbox mechanism blocked all 36 deliberately designed security test cases involving destructive commands, suspicious SQL patterns, and resource-intensive queries. These findings suggest that SQL Judge is technically feasible as a safe and responsive environment for SQL practice and formative assessment; however, larger-scale studies are still needed to validate grading accuracy, workload reduction, scalability, and educational effectiveness.
Authors: Nguyen Huu Bao, Le Xuan Hien, Pham Tho Hoan
Institution: Hanoi National University of Education
Language: English
Subfield: Computer Science Applications
Field: Computer Science
Domain: Physical Sciences
SDG: Quality education
Open Access status: bronze
Funder: Đại học Quốc gia Hà Nội
OpenAlex ID: W7222359244
