This is the second post in the series of From relational databases to databases with relations. Check the link to find all the other entries, too. The source code for everything, including the relational dataset is on GitHub: https://github.com/michael-simons/bootiful-music.The post has also been featured in This Week in Neo4j. To feel comfortable in a talk, […]
This post has been featured on This Week in Spring – November 8, 2016 and I’m so happy to be referred as “friend of the Spring community” 🙂 So, you have read through the previous parts of this series (1, 2 and 3) and you now have a Spring Boot project with jOOQ enabled, an […]
Most people slice their cakes like this: Image by Elaine Ashton and in most cases not horizontally but still many developers, like i did in the past, slice their packages that way. Really, just slapping classes into packages named “Model”, “View” and “Controller” doesn’t implement that pattern. @jensschauder has written much more eloquent than i […]
Some useful SQL Snippets: Oracle Create a date without any formatting hassle (like to_date): SELECT DATE’2014-01-01′ FROM dual;select date’2014-01-01′ from dual; Extract values as numbers from a date object SELECT EXTRACT (YEAR FROM DATE’2013-05-06’) FROM dual; SELECT EXTRACT (MONTH FROM DATE’2013-05-06’) FROM dual; SELECT EXTRACT (DAY FROM DATE’2013-05-06’) FROM dual;select extract (year from date’2013-05-06′) from […]
The Oracle Query Optimizer does a great job in rewriting Queries. For example the nested subquery in SELECT C.cust_last_name, C.country_id FROM customers C WHERE EXISTS (SELECT 1 FROM sales S WHERE S.quantity_sold > 1000 AND S.cust_id = C.cust_id);SELECT C.cust_last_name, C.country_id FROM customers C WHERE EXISTS (SELECT 1 FROM sales S WHERE S.quantity_sold > 1000 and […]