Tutorials

Excel shortcuts
30 Excel shortcuts to speed up your work
  • Web analytics

Excel shortcuts enable you to carry out your work a lot faster, but you first have to learn them. We present you with 30 useful Excel key combinations that faciliate your daily work. From navigation, to inserting cells, to calculating totals. If there isn’t already a shortcut for a function you regularly use, you can easily create your own Excel shortcuts.

30 Excel shortcuts to speed up your work
GraphQL
GraphQL: flexible query language and runtime environment for your web API
  • Web development

Applications on the web need interfaces in order to exchange data. If you run a web project yourself and want to grant other programs access to certain data sets, an API (application programming interface) like this is essential. Established concepts such as REST or SOAP are often used in development – but there are alternatives, as GraphQL proves.

GraphQL: flexible query language and runtime environment for your web API
Everything you need to know about e-books: e-book formats
Everything you need to know about e-books – part three: e-book formats
  • Online sales

Are you looking to publish an e-book and are searching for the right file format to suit your needs? In the third part of our series on e-books, we’ll be taking a closer look at the most popular e-book formats on the market today, comparing their advantages and disadvantages and helping you to decide which format is the right one for you.

Everything you need to know about e-books – part three: e-book formats
Raspberry Pi Plex
Raspberry Pi and Plex: how to turn a single-board computer into a media server
  • Configuration

Plex is among the most popular and user-friendly solutions for creating a media server in your home network. In contrast to many other applications, which are often Windows-only, the Plex server is compatible with Linux, Mac, and even single-board computers like the Raspberry Pi. In this Raspberry Pi and Plex tutorial, you will learn what technical requirements must be fulfilled and how...

Raspberry Pi and Plex: how to turn a single-board computer into a media server
Sequence diagrams
Sequence diagrams: depicting UML message exchanges
  • Web development

Sequence diagrams help you depict the message flow within a system in clear detail. A UML sequence diagram is a good choice for anyone who wants to understand a specific application case well. In object-oriented programming, sequence diagrams are suitable for checking the logic of a system. We’ll present these diagram types in detail and explain how to create a sequence diagram.

Sequence diagrams: depicting UML message exchanges
Deleting your PayPal
Deleting my PayPal account – what do I need to know?
  • Online sales

You do not have to provide any reasons to delete your PayPal account: If you find that you do not need or want to use your account anymore, then that’s enough to delete it. To do this, you don't even need to contact the service team directly, because in your profile settings you’ll find the option to delete your PayPal account quickly and easily.

Deleting my PayPal account – what do I need to know?
Class diagrams with UML
Creating class diagrams with UML
  • Web development

Class diagrams are structural diagrams in the UML modeling language. The UML class diagram is suitable for visualizing system elements and their dependencies for object-oriented programming languages. If you are a modeler creating a class diagram, it is advantageous to adhere to the official notation and semantics. This is the only way to avoid misunderstandings. We will explain notation for the...

Creating class diagrams with UML
How to enable cookies in your browser
How do I enable cookies in my web browser?
  • Website creation

Cookies save user information during website access to improve the page’s user-friendliness or record customer behavior. They’re responsible for noting down login data, browser settings, and other useful information so that you don’t have to set everything up again each time you visit the same site. Cookies can be completely or partially enabled, or just enabled for particular websites. How to...

How do I enable cookies in my web browser?
SQL JOIN
SQL JOIN – queries across multiple data tables
  • Technical matters

A major strength of the relational database model is that information is stored in separate database tables structured according to semantic relationships. This concept, known as normalization, is the basis for data storage that is as redundancy-free as possible, but requires a mechanism with which data from different tables can be merged for queries. The different JOIN types provide users with...

SQL JOIN – queries across multiple data tables
UML: Unified Modeling Language
UML - a graphical-type modeling language
  • Web development

If you need to run object-oriented programming, to represent a system clearly, and also make it accessible to external specialists, you may find the Universal Modeling Language to be ideal. UML is a modeling language, but has many other possible uses. Since the introduction of UML 2.0, UML diagrams are also suited to the graphical representation of non-computer-based concepts, such as use case...

UML - a graphical-type modeling language