I encountered a situation at work that I feel would be a good brain teaser. I was working on a project and needed a way to swap values from 2 different rows in a SQL table. Obviously I can do it on client side (like PHP) to do it; but that wouldn’t be a good [...]

There are times when you want to alter schema for all tables in the database. For example, let’s say in your project you have multiple databases with multiple tables on each of them. Suppose that you have columns within that table defined as DECIMAL(11,6). What it means is that the column will have 11 digits [...]

One of the golden rule of programming is to know about the function you are calling. You need to know what parameters it takes and what return values and type it gives back. For the most part, it’s not too hard to find that out. For MySQL, however, I found that it’s not always easy [...]

During development cycle, I often come to a case where I need to compare two tables whether they are the same or not. For example, if you already have a running script that outputs to a database table in production that was written sub-optimally and you need to improve it. You want to make sure [...]

There are times when auto increment is not sufficient. And there are times when what you need is actually a sequence. Unfortunately MySQL doesn’t have support for sequence. Having been working on PostgreSQL database as well, I found that it’s nextval() function is pretty nice. So in this article, I’d like to emulate (or implement) [...]