To NULL or not to NULL? Programming language designers inevitably have to decide whether they support NULLs or not. And they've proven to have a hard time getting this right. NULL is not intuitive in any language, because NULL is an axiom of that language, not a rule that can be derived from lower-level axioms. … Continue reading What if every object was an array? No more NullPointerExceptions!
This article is part of a series. You might also like: 10 More Common Mistakes Java Developers Make when Writing SQLYet Another 10 Common Mistakes Java Developers Make When Writing SQL Java developers mix object-oriented thinking with imperative thinking, depending on their levels of: Skill (anyone can code imperatively)Dogma (some use the "Pattern-Pattern", i.e. the … Continue reading 10 Common Mistakes Java Developers Make when Writing SQL
So far, I have been blogging about curious RDBMS caveats mostly related to Oracle and MySQL databases. Some examples: You never stop learning about Oracle features NOT IN vs. NOT EXISTS vs. LEFT JOIN / IS NULL: MySQL SQL incompatibilities: NOT IN and NULL values MySQL Bad Idea #384 But there are also other databases, … Continue reading 10 Things in SQL Server Which Don’t Work as Expected
I had recently discovered the JDK 8's addition of the Optional type. The Optional type is a way to avoid NullPointerException, as API consumers that get Optional return values from methods are "forced" to perform "presence" checks in order to consume their actual return value. More details can be seen in the Javadoc. A very … Continue reading On Java 8’s introduction of Optional