How to get the SQL query from JPQL or JPA Criteria
Introduction In this article, I’m going to show you how you can get the auto-generated SQL query from a JPQL or JPA Criteria API entity query.
SQL INNER JOIN – A Beginner’s Guide
Introduction In this article, we are going to see how INNER JOIN works in SQL, and how we can use it to associate rows belonging to different tables and build compound result sets.
Multiline String literals with Java Text Blocks
Introduction In this article, show you how the new Java Text Blocks can help you increase the readability of JPQL, SQL queries, or JSON string values. Back in 2005, I was developing a .NET project and really liked the C# Verbatim String Literal feature since it allows you to write a multiline string value without having to concatenate each individual line. The Java 13 Text Blocks feature now offers the possibility of creating a multiline Java String values.
SQL EXISTS and NOT EXISTS
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.
How to get the SQL execution plan on Oracle
Introduction In this article, we are going to see how we can get the SQL execution plan on Oracle. When tuning performance, the execution plan is indispensable as it allows you to understand the operations done by the database when executing a certain SQL query.
How to limit the SQL query result set to Top-N rows only
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.
