In SQL every column has a name, a type and a single value (that may be NULL in some cases). These strong guarantees makes working with SQL very nice. Nevertheless people seem intrigued by these “limitations” and propose “improvements”. Some of these improvements are: The ARRAY type in SQL99 and nested arrays in SQL2003. The JSON type in MySQL the JSON/JSONB type in PostgreSQL. The XML type in SQL Server. They all weaken the guarantee that a table row has a fixed number of keys and that every key has exactly one value and that each value has a specified type. ...

Installing the PHP SQL Server driver (PDO_SQLSRV) on a Debian 10 Linux system requires several steps, starting with the installation of the Microsoft ODBC Driver. Note that Debian requires TLS 1.2 and if your SQL Server does not support that you will run into “Error code 0x2746”. This post will explain how to resolve that issue. First we make sure to install the Microsoft ODBC Driver for SQL Server on Linux. ...

As we all know “naming things” is jokingly named as one of the two hard problems in software engineering (the other one being “cache invalidation”). This post is about the question whether your (database) table names should be plural or singular, e.g. “posts” or “post”. You should read the following Stack Overflow post to understand that this is a heated debate: Stack Overflow: Table Naming Dilemma: Singular vs. Plural Names ...

I have written open-source software that you can use as an alternative to Google/Microsoft Authenticator on any device (that Go can cross-compile for). You may (for instance) run it on your Raspberry Pi (zero) and use it as a “semi-hardware” token. The software does not (yet) support QR code scanning, so you you need to manually enter the name and secret to set up the token. Time-based One Time Passwords (TOTP) Time-based One Time Passwords (TOTP) is a technology where you agree on a shared secret with an authentication system. This shared secret is often shared via a QR code and stored in for instance a smartphone. The shared secret is combined with the UTC time in seconds in then hashed to produce a 6 digit code that is valid for 30 seconds. This is the protocol that is used by Google Authenticator and Microsoft Authenticator. ...

I bought a “Beelink Gemini T34” mini PC for 120 EUR with 8GB RAM, 128 mSATA SSD and a N3450 quad core 2.2 Ghz CPU with an Scenario Design Power (SDP) of only 4W. It is the successor of my “Beelink T4” mini PC with 4GB RAM, 64 GB eMMC and a Z8500 quad core 2.24 Ghz CPU. I run Xubuntu 20.04 on these boxes and you can run them as a low power (headless) server or as a HTPC (Home Theater PC) for Full-HD video. In this post we will unlock the full potential of the T34, by making it run much cooler and thus faster (as this avoids CPU throttle). ...

I have created a free GDPR scanner at: TQdev.com/gdpr-scanner. You can use it to see what domains are connected by your website and see who is running those domains and where they are hosted. Ideally you see only one entry with only the domain that you have entered in the web browser. In reality many websites use a lot of external services and thus also share your IP address and user agent with those services. Since this information is considered personal information this is subject to the GDPR. The GDPR says that you can only share this information if there is a need and a legal ground to do so OR a user consent. This scanner (that gives no consent) helps you identify services that information is shared with, so that you can consider whether or not you are GDPR compliant. ...

PHP-CRUD-API is an “automatic” API: software that turns your database into a REST API. This is possible thanks to database reflection (asking the database which tables and fields it has). Support for Docker and Docker Compose has been added and the Docker image is registered on Docker Hub. Test using Docker To do proper testing you may have to test the full matrix of all dependencies (PHP, MySQL, MariaDB, PostgreSQL, SQLite and SQL Server) and there corresponding versions. For PHP there are already 5 supported versions (7.0, 7.1, 7.2, 7.3 and 7.4), for MySQL there are 3 supported versions (5.6 5.7 and 8.0) and for PostgreSQL there are 9 supported versions (9.1, 9.2, 9.3, 9.4, 9.5, 9.6, 10, 11 and 12). Only these combinations of these major versions would lead to 5 x 3 + 5 x 9 = 50 test runs. ...

When you buy a second hand Mac you should do a clean install of OSX from a USB drive for security reasons. This sounds easy, but there are some problems you may run into. In this post we discuss 2 common, but cryptic, error messages and explain how to avoid them. Note that a clean installation requires you to have a USB drive with a bootable OSX installer. Note that on newer Macs you don’t need an USB drive as these support macOS Recovery over the Internet by pressing Option-Command-R after boot. ...

On Xubuntu I protect my privacy by using an ad-blocker (uBlock Origin) in my browser (Firefox). On my phone (Android) I also use Firefox, but I was not able to install uBlock Origin in Firefox on Android, until now! I tried it again today and on my Android 10 (Android One) Xiaomi A3 with Firefox 68.9.0 and it just works. For me this is huge, as this makes surfing the web on my phone a viable option. Until now is was minimizing browser usage on my phone, due to privacy concerns. ...

I bought a “Beelink T4” mini PC for 100 EUR with 4GB RAM, 64 GB eMMC and a Z8500 quad core 2.24 Ghz CPU with an Scenario Design Power (SDP) of only 2W. It is the successor of my “Z83II” mini PC with 2GB RAM, 32 GB eMMC and a Z8350 quad core CPU. I run Xubuntu 20.04 on these boxes and you can run them as a low power (headless) server or as a HTPC (Home Theater PC) for Full-HD video. In this post we will unlock the full potential of the T4, making it run a little faster and much cooler. ...