2019

Taipalus, Toni

Structured Query Language (SQL) is still the de facto database query language widely used in industry and taught in almost all university level database courses. The role of SQL is further strengthened by the emergence of NewSQL systems which use SQL as their query language as well as some NoSQL systems, e.g., Cassandra and DynamoDB, which base their query languages on SQL. Even though the syntax of SQL is relatively simple when compared to programming languages, studies suggest that students struggle with simple concepts due to working memory constraints when learning SQL. This teaching tip presents a novel, simple, and intuitive notation for planning more complex SQL queries, which 1) facilitates the learning of SQL by providing students with a big picture of a particular data demand in regard to the database structure and 2) separates the logic of a data demand from the syntax and semantics of SQL, thus alleviating the strain on the student’s short-term memory. The notation can also be applied when discussing SQL semantics during the teaching process without focusing on the syntactical nuances of the language.