I’ve just stumbled upon this great post by Vlad Mihalcea, titled The Best Way to Fetch a Spring Data JPA DTO Projection. It got some nice traction on reddit, too. This is such a nice use-case and apt solution, I wanted to quickly show the second best way of doing the same, with jOOQ this … Continue reading The Second…
#nested collections
4 posts
30 Aug 2022
9 May 2022
A really cool, recent question on Stack Overflow was about how to map a nested collection into a Java Map with jOOQ. In the past, I’ve blogged about the powerful MULTISET operator many times, which allows for nesting collections in jOOQ. This time, instead of nesting data into a List<UserType>, why not nest it in … Continue reading How to…
9 Oct 2020
One of the main features of ORMs is M as in Mapping. Libraries like jOOQ help auto-mapping flat or nested database records onto Java classes that have the same structure as the SQL result set. The following has always been possible in jOOQ, assuming PostgreSQL’s INFORMATION_SCHEMA (using the generated code from the jOOQ-meta module): The … Continue reading Nesting Collections…
10 Feb 2017
Sometimes, SQL can just be so beautiful. One of the less mainstream features in SQL is the array type (or nested collections). In fact, it’s so not mainstream that only 2 major databases actually support it: Oracle and PostgreSQL (and HSQLDB and H2 in the Java ecosystem). In PostgreSQL, you can write: Or in Oracle: … Continue reading Beautiful SQL:…