@[toc](QueryDB Outline) ## Introduction to Querying ## Introduces the fundamental operations to retrieve data from a relational database, including set operations, horizontal and vertical filtering, and join. Using this context, the visualization provides an overview of the SQL industry-standard query language by incrementally building a textual query that corresponds to its visual representation.  ### Query: Motivation to identify data and relationships.  ---------- ### Sets: Common set operators.  ---------- ### Filtering: Operations to horizontally and vertically filter data.  ---------- ### Joining: More ways of combining tables of data that require a form of filtering.  ---------- ### SQL: Introduction to querying using SQL.  ---------- ### Checkpoint: Quiz yourself.  > 20 multiple choice and True-False questions provide a formative > self-assessment component for the learner. ---------- ## Pedagogy ## Besides assigning the formative self-assessment with a performance goal for participation credit, the use of a cooperative learning exercise in class is highly recommended. The [sample cooperative learning exercise][1] asks students to write queries involving: - horizontal filtering only - vertical filtering only - horizontal and vertical filtering - join only - join with horizontal filtering - join with horizontal and vertical filtering using the [supporting Access database][2] and a [worksheet][3] for recording their Access query. The QBE interface of Access inherently supports the design aspect of answering a query and illustrates the primary-foreign key relationships. Note that the class discussion can compare the approaches used to answer the queries in Access and in SQL, comparing the SQL View in Access to the SQL solution. If more practice of database querying is desired by the instructor, the students can explore the various queries presented in the Students Taking Courses visualization using either Access or the SQL standard: - [Students Access database][4] - [StudentsMySQL.zip][5] An annotated [companion document][6] with numerous screen shots illustrates the Access QBE and SQL statements to answer each query in the QueryDB visualization. ---------- ## Source Code ## The OSF FLEX Source Code folder contains the exported Flash Builder project for QueryDB: [QueryDBMain.fxp][7] ---------- [1]: https://osf.io/enr6d/ "QueryDB Cooperative Exercise" [2]: https://osf.io/sb4zh/ "Employee Department Cooperative Exercise Access Database" [3]: https://osf.io/hxqgc/ "Worksheet for Access and SQL Query" [4]: https://osf.io/q7apc/ "Students Access Database" [5]: https://osf.io/n4xrm/ "Students MySQL Zip" [6]: https://osf.io/zgs37/ "Comparison of QueryDB Queries in Access and SQL" [7]: https://osf.io/pq6nj/ "QueryDBMain.fxp"