Home » Author Archives: Lukas Eder (page 2)

Author Archives: Lukas Eder

Lukas is a Java and SQL enthusiast developer. He created the Data Geekery GmbH. He is the creator of jOOQ, a comprehensive SQL library for Java, and he is blogging mostly about these three topics: Java, SQL and jOOQ.

Reactive Database Access – Part 1 – Why “Async”

software-development-2-logo

We’re very happy to announce a guest post series on the jOOQ blog by Manuel Bernhardt. In this blog series, Manuel will explain the motivation behind so-called reactive technologies and after introducing the concepts of Futures and Actors use them in order to access a relational database in combination with jOOQ. Manuel Bernhardt is an independent software consultant with a ...

Read More »

Reactive Database Access – Part 2 – Actors

akka-logo

We’re very happy to continue our a guest post series on the jOOQ blog by Manuel Bernhardt. In this blog series, Manuel will explain the motivation behind so-called reactive technologies and after introducing the concepts of Futures and Actors use them in order to access a relational database in combination with jOOQ. Manuel Bernhardt is an independent software consultant with ...

Read More »

How to Fill Sparse Data With the Previous Non-Empty Value in SQL

software-development-2-logo

The following is a very common problem in all data related technologies and we’re going to look into two very lean, SQL-based solutions for it: How do I fill the cells of a sparse data set with the “previous non-empty value”? The problem The problem is really simple and I’m reusing the example provided by Stack Overflow user aljassi in ...

Read More »

SQL GROUP BY and Functional Dependencies: A Very Useful Feature

software-development-2-logo

Relational databases define the term “Functional Dependency” as such (from Wikipedia): In relational database theory, a functional dependency is a constraint between two sets of attributes in a relation from a database. In other words, functional dependency is a constraint that describes the relationship between attributes in a relation. In SQL, functional dependencies appear whenever there is a unique constraint ...

Read More »

3 Reasons why You Shouldn’t Replace Your for-loops by Stream forEach

java-logo

Awesome! We’re migrating our code base to Java 8. We’ll replace everything by functions. Throw out design patterns. Remove object orientation. Right! Let’s go! Wait a minute Java 8 has been out for over a year now, and the thrill has gone back to day-to-day business. A non-representative study executed by baeldung.com from May 2015 finds that 38% of their ...

Read More »

A Subtle AutoCloseable Contract Change Between Java 7 and Java 8

java-logo

A nice feature of the Java 7 try-with-resources statement and the AutoCloseable type that was introduced to work with this statement is the fact that static code analysis tools can detect resource leaks. For instance, Eclipse: When you have the above configuration and you try running the following program, you’ll get three warnings: public static void main(String[] args) throws Exception ...

Read More »

Beware of Functional Programming in Java!

java-logo

This isn’t going to be a rant about functional programming, which is awesome. This is a warning about some practices that you are very likely going to apply to your code, which are terribly wrong!. Higher order functions are essential to functional programming, and thus, talking about them will help you be the center of attention at parties. If you’re ...

Read More »

How to Find the Longest Consecutive Series of Events in SQL

software-development-2-logo

A very interesting problem that can be solved very easily with SQL is to find consecutive series of events in a time series. But what is a consecutive series of events in a time series? Take Stack Overflow, for example. Stack Overflow has a cool reputation system that uses badges to reward certain behaviour. As a social website, they encourage ...

Read More »

Want to take your Java skills to the next level?

Grab our programming books for FREE!

Here are some of the eBooks you will get:

  • Advanced Java Guide
  • Java Design Patterns
  • JMeter Tutorial
  • Java 8 Features Tutorial
  • JUnit Tutorial
  • JSF Programming Cookbook
  • Java Concurrency Essentials