I recently stumbled upon a standard SQL feature that was implemented, to my surprise, in HSQLDB. The keyword is CORRESPONDING, and it can be used with all set operations, including UNION, INTERSECT, and EXCEPT. Let's look at the sakila database. It has 3 tables with people in it: CREATE TABLE actor ( actor_id integer NOT … Continue reading A Rarely Seen, but Useful SQL Feature: CORRESPONDING
Tag: HSQLDB
Using SQL to Calculate the Popularity (on Stack Overflow) of Derby, H2, and HSQLDB
Few people know about this very very awesome feature of the Stack Exchange platform. The Stack Exchange Data Explorer To be found here: http://data.stackexchange.com As you may know, much of the Stack Exchange platform runs on SQL Server (interesting architecture details here: http://stackexchange.com/performance), and the team has had the courtesy of making a lot of … Continue reading Using SQL to Calculate the Popularity (on Stack Overflow) of Derby, H2, and HSQLDB
jOOQ Tuesdays: Thomas Müller Unveils How HSQLDB Evolved into the Popular H2 Database
Welcome to the jOOQ Tuesdays series. In this series, we’ll publish an article on the third Tuesday every other 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 pleasure … Continue reading jOOQ Tuesdays: Thomas Müller Unveils How HSQLDB Evolved into the Popular H2 Database
Counting Distinct Records in SQL
The SQL language and its depths... Some of you readers might be aware of MySQL's capability of counting distinct records through the COUNT() aggregate function. The MySQL documentation reads: COUNT(DISTINCT expr,[expr...]) Returns a count of the number of rows with different non-NULL expr values. In other words, you can count distinct first and last names very easily: SELECT … Continue reading Counting Distinct Records in SQL
How to use H2 with jOOQ
Living through the latest developments of the H2 and HSQLDB databases has been very exciting for me as jOOQ developer. Those two databases have a common heritage and share a lot of functionality. Both are progressing at a high pace with a very active community around their respective lead developers. I have recently posted an … Continue reading How to use H2 with jOOQ