A Notation for Planning SQL Queries

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

MSGI: MySQL Graphical Interface

The current development in data processing technology and the current revolution in office information systems require a very efficient database end user interface capable of satisfying the requirements of the increasing spectrum of end user. Studies in this respect have shown that the graphical specification for such an interface is more successful than the linear and the natural language specifications.In this paper, MSGI (MySQL Graphical Interface) design and implementation are presented. It is an easy to use and easy to learn graphical database end user interface, running on the PC with any platform, to provide a comprehensive facility for accessing databases managed and controlled by MySQL database management systems. Keywords: Graphical End-User Interface, Database End-User Interface, MySQL Graphical Interface, Graphical Database Interface

Identifying SQL misconceptions of novices: findings from a think-aloud study

SQL is the most commonly taught database query language. While previous research has investigated the errors made by novices during SQL query formulation, the underlying causes for these errors have remained unexplored. Understanding the basic misconceptions held by novices which lead to these errors would help improve how we teach query languages to our students. In this paper we aim to identify the misconceptions that might be the causes of documented SQL errors that novices make. To this end, we conducted a qualitative think-aloud study to gather information on the thinking process of university students while solving query formulation problems. With the queries in hand, we analyzed the underlying causes for the errors made by our participants. In this paper we present the identified SQL misconceptions organized into four top-level categories: misconceptions based in previous course knowledge, generalization-based misconceptions, language-based misconceptions, and misconceptions due to an incomplete or incorrect mental model. A deep exploration of misconceptions can uncover gaps in instruction. By drawing attention to these, we aim to improve SQL education.Algorithms and the Foundations of Software technolog

A Survey on Array Storage, Query Languages, and Systems

Since scientific investigation is one of the most important providers of massive amounts of ordered data, there is a renewed interest in array data processing in the context of Big Data. To the best of our knowledge, a unified resource that summarizes and analyzes array processing research over its long existence is currently missing. In this survey, we provide a guide for past, present, and future research in array processing. The survey is organized along three main topics. Array storage discusses all the aspects related to array partitioning into chunks. The identification of a reduced set of array operators to form the foundation for an array query language is analyzed across multiple such proposals. Lastly, we survey real systems for array processing. The result is a thorough survey on array data storage and processing that should be consulted by anyone interested in this research topic, independent of experience level. The survey is not complete though. We greatly appreciate pointers towards any work we might have forgotten to mention.Comment: 44 page

Exploring the prevalence of SQL misconceptions: a study design

The Structured Query Language (SQL) is an established language for data manipulation in relational databases. It is widely used in industry, and therefore part of the typical Computer Science curriculum. From the large amounts of mistakes higher education students make while learning and using SQL, we know that this language is not easy to learn. Various researchers have examined the types of mistakes SQL novices make, and recently, the first step towards understanding the underlying reasons for these mistakes has been made. In this poster abstract, we propose a study to examine the prevalence of these origins, also called misconceptions. We hope the Computer Science Education community will help us reflect on and strengthen our methodology, and ultimately, our findings.Algorithms and the Foundations of Software technolog

Data-Driven Database Education: A Quantitative Study of SQL Learning in an Introductory Database Course

The Structured Query Language (SQL) is widely used and challenging to master. Within the context of lab exercises in an introductory database course, this thesis analyzes the student learning process and seeks to answer the question: ``Which SQL concepts, or concept combinations, trouble students the most?\u27\u27 We provide comprehensive taxonomies of SQL concepts and errors, identify common areas of student misunderstanding, and investigate the student problem-solving process. We present an interactive web application used by students to complete SQL lab exercises. In addition, we analyze data collected by this application and we offer suggestions for improvement to database lab activities

Accelerating SQL with Complex Visual Querying

This dissertation addresses the usability improvement of a graphical user interface that allows query formulation without using textual query languages, such as SQL. This visual tool, called Aggregates, is provided on the OutSystems Low-Code Development Platform, to formulate data queries, through interaction and manipulation of visual components. Since Aggregates do not support all the existing functionalities of SQL, the OutSys- tems Platform allows users to build queries using this textual query language. Nonethe- less, by evaluating customers’ SQL queries, it was revealed that a considerable subset of the queries written in SQL could have been formulated using the visual tool. The users’ interviews and the results of the SQL queries evaluation have foreseen that the cause of the reduced acceptance of the visual approach, could be the existing usability problems on the interface. Furthermore, the interface is inadequate to build more complex queries, which involve more entities and conditions. Through an iterative design process, this dissertation includes the design, implemen- tation, and evaluation of prototypes with different fidelity levels. The aim is to optimize the effectiveness and efficiency of the process where users communicate to the system what data they intend to extract from the database. Moreover, the readability and com- prehension improvement of the query visual representation is intended, reducing the time and the effort required to understand what data will be gathering from the database. The final implemented interface is currently incorporated on the OutSystems Platform to accelerate the query formulation process without harming the learnability of the system.Esta dissertação apresenta um estudo sobre o melhoramento da usabilidade de uma inter- face gráfica que permite consultar dados sem recorrer a linguagens de consulta textuais, tais como o SQL. A ferramenta visual abordada, denominada Aggregates, está inserida na Plataforma de Desenvolvimento Low-Code OutSystems, de modo a permitir a formula- ção de consultas a bases de dados, através da interação e manipulação de componentes visuais. Tendo em conta que a interface gráfica disponibilizada não suporta todos os tipos de consultas suportadas pelo SQL, os utilizadores podem recorrer a esta linguagem textual para construir as suas pesquisas. No entanto, ao avaliar estas consultas criadas textual- mente em SQL, por clientes da plataforma, percebeu-se que um conjunto considerável de consultas foram construídas usando SQL, embora pudessem ter sido construídas usando a ferramenta visual disponibilizada. Tanto as entrevistas aos utilizadores, como a análise das consultas construídas usando SQL, indicaram que a falta de aceitação do método visual de construção de consultas era causada por problemas de usabilidade na interface. Para além disso, quando as consultas de dados envolvem mais entidades ou condições, os utilizadores sentem dificuldade a usar a interface. Através de um processo de desenho iterativo, esta dissertação apresenta o desenho, im- plementação e avaliação de protótipos com diferentes níveis de fidelidade. Foi optimizada a eficácia e a eficiência do processo de utilização da interface para consultar dados. Além disso, também se melhorou a legibilidade da representação visual da consulta, de modo a diminuir o tempo e esforço necessário para compreender que dados pretendem ser extraídos da base de dados. A implementação final da interface encontra-se atualmente incorporada na Plataforma OutSystems, acelerando o processo de criação de consultas de dados sem dificultar a aprendizagem necessária para utilizar o sistema