Abstract In Structured Query Language (SQL) education, students often execute queries against a simple exercise database. Recently, databases that are more realistic have been utilized to the effect that students find exercises more interesting and useful, as these databases more accurately mimic databases students are likely to encounter in their future work environments. However, using even the most engaging database can be counterproductive to learning, if a student is not able to formulate correct queries due to the complexity of the database schema. Scientific evidence on the effects of database complexity on student’s query formulation is limited, and with queries from 744 students against three databases of varying logical complexity, we set out to study how database complexity affects the success rates in query formulation. The success rates against a simple database were significantly higher than against a semi-complex and a complex database, which indicates that it is easier for students to write SQL queries against simpler databases. This suggests, at least in the scale of our exercise databases, that educators should also consider the negative effects of more realistic databases, even though they have been shown to increase student engagement.

中文翻译：

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数据库复杂性对 SQL 查询公式的影响

摘要 在结构化查询语言 (SQL) 教育中，学生经常针对简单的练习数据库执行查询。最近，更现实的数据库已被用来使学生发现练习更有趣和有用，因为这些数据库更准确地模拟了学生在未来工作环境中可能会遇到的数据库。但是，如果学生由于数据库模式的复杂性而无法制定正确的查询，那么即使使用最吸引人的数据库也可能对学习产生反作用。关于数据库复杂性对学生查询制定的影响的科学证据是有限的，通过 744 名学生对三个不同逻辑复杂性的数据库的查询，我们着手研究数据库复杂性如何影响查询制定的成功率。针对简单数据库的成功率明显高于针对半复杂和复杂数据库的成功率，这表明学生更容易针对较简单的数据库编写 SQL 查询。这表明，至少在我们练习数据库的规模上，教育工作者还应该考虑更现实的数据库的负面影响，即使它们已被证明可以提高学生的参与度。