Blog Archive

  • Refitting Filtered Map Points

    Using a public dataset of New York City high schools, I built a page that lets students or parents filter the list based on various criteria. As they narrow their options, a map region reflects where the remaining schools are located, and a stacked bar chart lets them compare the contenders on a few important metrics. While the map initially centered and zoomed itself to fit the unfiltered set of schools, to give users the sense of “homing in” on their perfect school I wanted to refit the map around the narrowed search results. To reflect the filtered results from…

  • Declarative Data-Driven Downloads

    While developing APEX apps, on multiple occasions I’ve needed to generate data-driven artifacts for external use. My app lets staff manage the data that drives their organization, but for historical reasons a related public-facing website can’t be replaced in the near term. The site is usually static files or was built years before on a different tech stack like LAMP (Linux, Apache, MySQL, PHP). This article walks through a simple example of generating all the HTML files for a static website based on database data. It uses a declarative “transform group” capability I wrote for myself to combine the declarative…

  • Data-Driven Diagrams

    I often want to visualize my Oracle APEX app’s data model as an Entity/Relationship diagram to remind myself how tables are related and exactly how columns are named. After recently stumbling on the open source Mermaid JS project, I had a lightbulb moment and set out to build my own data model visualizer app with APEX itself. Mermaid Diagram Syntax The Mermaid JS open source project aims to improve software documentation quality with an easy-to-maintain diagram syntax for Markdown files. The typical README.md file of a software project can include an Entity/Relationship diagram by simply including text like this: Including…

  • Oracle APEX Grand Tour

    I joined the APEX dev team in 2021 after falling in love with its low-code app-building productivity and ability to fully embrace the Oracle database. But when I looked for a unified demo and presentation showcasing all its low-code features, I came up empty-handed. Over the following months, I learned everything I could and created the one hour webinar I wished had existed when I was starting out with the product. The goal? Educate the viewer on what is possible with APEX by seeing it in action. If you’re reading this blog, you probably have already employed most of APEX’s…

  • Building a Mini SQL Workshop #JoelKallmanDay

    Two new features in APEX 22.2 let me easily create a Mini SQL Workshop app. Users type any query in a code editor and instantly visualize the resulting data. I wired my colleague Ronny Weiss’ Monaco Code Editor region plug-in to a new CLOB-valued page item to support editing the SQL query. A dynamic action reacts to the code editor save event to refresh the new Dynamic Content region to show the query’s results. For an interesting twist, the database’s native support for XML and XSLT produces the HTML markup for the dynamic content region rather than looping over data…