Home » Author Archives: Lukas Eder (page 11)

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.

Don’t be “Clever”: The Double Curly Braces Anti Pattern

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From time to time, I find someone using the double curly braces anti pattern (also called double brace initialisation) in the wild. This time on Stack Overflow: Map source = new HashMap(){{ put("firstName", "John"); put("lastName", "Smith"); put("organizations", new HashMap(){{ put("0", new HashMap(){{ put("id", "1234"); }}); put("abc", new HashMap(){{ put("id", "5678"); }}); }}); }}; In case you do not understand the ...

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jOOQ Tuesdays: Yalim Gerger brings Git to Oracle

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We’re excited to launch a new series on our blog: the jOOQ Tuesdays. In this series, we’ll publish an article on the third Tuesday every month where we interview someone we find exciting in our industry from a jOOQ perspective. This includes people who work with SQL, Java, Open Source, and a variety of other related topics. We have the ...

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Really Too Bad that Java 8 Doesn’t Have Iterable.stream()

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This is one of the more interesting recent Stack Overflow questions: Why does Iterable not provide stream() and parallelStream() methods? At first, it might seem intuitive to make it straight-forward to convert an Iterable into a Stream, because the two are really more or less the same thing for 90% of all use-cases. Granted, the expert group had a strong ...

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The Inconvenient Truth About Dynamic vs. Static Typing

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Sometimes there are these moments of truth. They happen completely unexpectedly, such as when I read this tweet: Good discussion of Facebook Flow – http://t.co/5KTKakDB0w — David J. Pearce (@whileydave) November 23, 2014 David is the author of the lesser-known but not at all lesser-interesting Whiley programming language, a language that has a lot of static type checking built in ...

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Do You Really Understand SQL’s GROUP BY and HAVING clauses?

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There are some things in SQL that we simply take for granted without thinking about them properly. One of these things are the GROUP BY and the less popular HAVING clauses. Let’s look at a simple example. For this example, we’ll reiterate the example database we’ve seen in this previous article about the awesome LEAD(), LAG(), FIRST_VALUE(), LAST_VALUE() functions:   ...

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Use MySQL’s Strict Mode on all new Projects!

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MySQL is a database that has been bending the SQL standard in ways that make it hard to move off MySQL. What may appear to be a clever technique for vendor lockin (or maybe just oversight of the standard) can be quite annoying in understanding the real meaning of the SQL language. One such example is MySQL’s interpretation of how ...

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Don’t Miss out on Awesome SQL Power with FIRST_VALUE(), LAST_VALUE(), LEAD(), and LAG()

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If you’re using a commercial database or PostgreSQL / Firebird / CUBRID, you will be able to take advantage of the full power of window functions. We’ve blogged about window functions’ awesomeness a couple of times, in particular about ROW_NUMBER(), RANK(), DENSE_RANK(). Today, we’re going to look into some awesome window functions that produce values of other rows that are ...

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Don’t Migrate to MariaDB just yet. MySQL is Back!

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Now that I have your attention, I’d like to invite you to a critical review of where we’re at in the MySQL vs. MariaDB debate. Around one month ago, I visited Oracle Open World 2014, and I’ve met with Morgan Tocker, the MySQL community manager at Oracle to learn about where MySQL is heading. Who “is” MySQL An interesting learning ...

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