Introduction In this article, we are going to see how the SQL EXISTS operator works and when you should use it. Although the EXISTS operator has been available since SQL:86, the very first edition of the SQL Standard, I found that there are still many application developers who don’t realize how powerful SQL subquery expressions really are when it comes to filtering a given table based on a condition evaluated on a different table.
Introduction In this article, we are going to see how a CROSS JOIN works, and we will also make use of this SQL join type to build a poker card game.
Introduction While developing a Spring Boot application is rather easy, tuning the performance of a Spring Boot application is a more challenging task, as, not only it requires you to understand how the Spring framework works behind the scenes, but you have to know what is the best way to use the underlying data access framework, like Hibernate for instance. In a previous article, I showed you how easily to optimize the performance of the Petclinic demo application. However, by default, the Petclinic Spring Boot application uses the in-memory HSQLDB database, which… Read More
Introduction In this article, we are going to see how a deadlock can occur in a relational database system, and how Oracle, SQL Server, PostgreSQL, or MySQL recover from a deadlock situation.
Introduction Ever wanted to connect to a relational database using Java and didn’t know which JDBC Driver Maven dependency to use? If so, this article is surely going to help you from now on.
Introduction In this article, we are going to see how we can limit the SQL query result set to the Top-N rows only. Limiting the SQL result set is very important when the underlying query could end up fetching a very large number of records, which can have a significant impact on application performance.