SQL Server OPENJSON – Map JSON to a relational table

Introduction In this article, I’m going to explain how the SQL Server OPENJSON function works and how it can help you transform a JSON object into a relational database table. When using a relational database system, it’s a very good idea to design the database schema according to the relational model. However, there are specific situations when the relational model is way too strict, and that’s when a JSON column type might be very handy. For instance, as I explained in this article, when designing an audit log table, it’s much more… Read More

Hash Join Algorithm

Introduction In this article, we are going to see how the Hash Join Algorithm works and when it’s suitable for a relational database system to employ it in order to execute an SQL JOIN query.

Nested Loop Join Algorithm

Introduction In this article, we are going to see how the Nested Loop Join Algorithm works and when it’s suitable for a relational database system to employ it in order to execute an SQL JOIN query.

High-Performance Java Persistence Newsletter, Issue 22

Introduction Welcome to a new issue of the High-Performance Java Persistence Newsletter in which we share articles, videos, workshops, and StackOverflow answers that are very relevant to any developer who interacts with a database system using Java.

High-Performance Java Persistence Newsletter, Issue 21

Introduction Welcome to a new issue of the High-Performance Java Persistence Newsletter in which we share articles, videos, workshops, and StackOverflow answers that are very relevant to any developer who interacts with a database system using Java.

Mapping Java Records to JSON columns using Hibernate

Introduction In this article, I’m going to explain how we can map Java Records to JSON columns when using Hibernate. Because Hibernate ORM does not offer built-in support for JSON, we are going to use the Hiberate Types library, which allows you to map entity attributes to JSON column types, no matter if you are using Oracle, SQL Server, PostgreSQL, or MySQL.

SQL Server audit logging using triggers

Introduction In this article, we are going to see how we can implement an audit logging mechanism using SQL Server database triggers to store both the previous and the current state of a given target table record in JSON column types.

High-Performance Java Persistence Newsletter, Issue 18

Introduction Welcome to a new issue of the High-Performance Java Persistence Newsletter in which we share articles, videos, workshops, and StackOverflow answers that are very relevant to any developer who interacts with a database system using Java.

SQL ANY Operator – A Beginner’s Guide

Introduction In this article, we are going to see how the ANY operator works in SQL using it with a subquery or a VALUES clause, as well as its NULL value handling behavior.

SQL LEFT JOIN – A Beginner’s Guide

Introduction In this article, we are going to see how LEFT JOIN works in SQL, and how we can use it to associate rows belonging to different tables and build compound result sets. Unlike JOIN or INNER JOIN, LEFT JOIN is an OUTER JOIN. So, LEFT JOIN and LEFT OUTER JOIN are equivalent. Other OUTER JOIN types are RIGHT OUTER JOIN and FULL OUTER JOIN. However, since the SQL OUTER keyword is superfluous, it’s usually omitted.