SQL Archives - Philipp Salvisberg's Blog

2025-07-12

Outer Joining With ANSI SQL-89 and SQL-92

2025-07-12

Categories

Oracle

Outer Joining With ANSI SQL-89 and SQL-92

Introduction I recently implemented a quick fix for the rule G-3130 to transform queries to ANSI SQL-92 syntax. One of the challenges was to handle Oracle’s outer-join syntax (+). In ANSI SQL-89, join and filter criteria are part of the WHERE clause. It’s not easy to distinguish them. In this blog post, […]

2025-03-18

Categories

Oracle

dbLinter Rules Repository

Introduction Today I proudly announce that the Joint Venture between United Codes and Grisselbav released the initial version of the dbLinter Rules Repository website. This is the first publicly available component of the dbLinter tool suite. What is dbLinter? dbLinter is a suite for checking and improving the quality of database applications. […]

2025-03-08

2025-03-08

Categories

Oracle

Wrapping and Unwrapping PL/SQL

Introduction Today I released a PL/SQL Unwrapper for VS Code. You can find it in the VS Code Marketplace, along with instructions on how to use it. It’s super easy and works the same way as the extension I wrote 10 years ago for SQL Developer in Java. If you’re curious about […]

2025-01-28

Avoid Implicit Type Conversion in JSON Access

2025-01-28

Categories

Oracle

Avoid Implicit Type Conversion in JSON Access

Introduction Before comparing two values, the Oracle Database automatically ensures that both values have the same data type. It converts one of the values to match the data type of the other value. The SQL Language Reference manual describes when and how implicit data conversions happen. However, Oracle recommends that you convert […]

2024-12-24

Evolution of a SQL Domain for Semantic Versioning

2024-12-24

Categories

Oracle

Evolution of a SQL Domain for Semantic Versioning

1. Introduction In my current project, I use a SQL domain to implement the formatting and precedence rules for Semantic Versioning. I started with a simple implementation covering only the most basic rules. Getting the sorting right is key in my project. It allows me to identify the latest compatible version of […]

2024-09-30

2024-09-30

Categories

Oracle

How Many Bytes Are in an Emoji?

What Is a Byte? A byte is made up of 8 bits. And in the old days, it represented a character. If you use a single-byte character set such as WE8MSWIN1252, WE8ISO8859P15 or similar, it still is. What Is a Character? We can find definitions for example on Wikipedia and in the […]

2024-07-29

IslandSQL Final Episode 10: Parsing PL/pgSQL

2024-07-29

Categories

Oracle

IslandSQL Final Episode 10: Parsing PL/pgSQL

Introduction IslandSQL is a parser for SQL files targeting OracleDB or PostgreSQL. The parser is available on Maven Central and can process SQL*Plus, SQLcl or psql statements besides SQL statements. However, the focus is on statements with static DML statements and code in PL/SQL and PL/pgSQL. For static code analysis, for example. […]

2024-06-27

IslandSQL Episode 9: GraphQL, JSON and Flexible Schemas With Duality Views

2024-06-27

Categories

Oracle

IslandSQL Episode 9: GraphQL, JSON and Flexible Schemas With Duality Views

Introduction In the last episode, we looked at some new features in Oracle Database 23.4. The IslandSQL grammar now covers all statements that can contain static DML statements and code in PL/SQL and PL/pgSQL. While implementing the ANTLR grammar for the create JSON relational duality view statement I stumbled over GraphQL in […]

2024-06-15

IslandSQL Episode 8: What's New in Oracle Database 23.4?

2024-06-15

Categories

Oracle

IslandSQL Episode 8: What’s New in Oracle Database 23.4?

Introduction In the last episode, we looked at some features in PostgreSQL which I miss in the Oracle Database. The IslandSQL grammar now covers PL/SQL and the related DDL statements. The implementation was more complex than expected, mainly because of the incompatibilities between PostgreSQL and the Oracle Database. I will probably deal […]

2024-03-23

IslandSQL Episode 7: DML Statements in PostgreSQL 16 and What I Miss in Oracle Database 23c

2024-03-23

Categories

Oracle

IslandSQL Episode 7: DML Statements in PostgreSQL 16 and What I Miss in Oracle Database 23c

Introduction In the last episode, we covered DML statements in SQL*Plus/SQLcl scripts for the Oracle Database 23c. The IslandSQL grammar can now also handle PostgreSQL 16 DML statements in psql scripts. In this blog post, we will look at some features in PostgreSQL 16 which I miss in the Oracle Database 23c. […]