This article is the Japanese version of a post published on STEALIEN's Korean technical blog in December 2022. It introduces ...

PostgreSQL subqueries allow one SQL query to run inside another, making it possible to solve filtering, aggregation, comparison, and table based problems without writing separate queries. The lesson ...

Let's break down when it's ideal to use the NOLOCK hint and when you should never use it. As a consultant, I work on wide swaths of database systems, which means I get to see many, many SQL statements ...

Microsoft introduced the Query Store when they released SQL Server 2016 and it can track statement performances, pinpoint queries and more. DBTA recently held a webinar focused on the new features and ...

PostgreSQL CASE statements make it possible to add conditional logic directly into SQL queries, working similarly to IF ELSE statements in programming languages and spreadsheet tools. This tutorial us ...

A common SQL habit is to use SELECT * on a query, because it’s tedious to list all the columns you need. Plus, sometimes those columns may change over time, so why not just do things the easy way? But ...