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Your SQL IS NOT JavaScript (neither PHP)

IS NULL, IS NOT NULL, truthiness among other assertions on MySQL and PostgreSQL

People like to complain about JavaScript, how can one thing be equal to the other, i.e. null == undefined evaluates to true unless you use the triple equals ===. Other dynamic typed languages have its peculiarities, such as Ruby where 0 == true evaluates to true, the reason for Ruby is that considers 0 as a value and any value evaluates to true.

How about SQL? The answer is… it depends.

Which database are you using?

Some may be more forgiving, like MySQL doing casts for you all over the place, or more strict like PostgreSQL where you can only compare the truthiness of something of the same type.

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Extending WordPress Dockerfile to use MySQL 5.7 (or 8.0)

Oracle’s website shows End of life for MySQL 5.5 as of Jan 20th of 2019, so hurry up and upgrade!

I am working building some demos for Cloud SQL and one of the requirements I had was to run MySQL 5.7 and WordPress as my sample application. The demo consisted on migrating from a single VM environment with WordPress and MySQL running alongside. The narrative: the site got popular and the database became the bottle neck because of all the shared resources between them and the application. The proposed solution? A minimal downtime migration to Cloud SQL, moving the data layer to a dedicated server.

I am going to be doing this demo a lot of times, so I needed some way to automate it. I thought of doing through Docker. I am not Docker proficient, and to begin with I asked …

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Replication from External Primary/Leader into GCP

This is a post based on recent tutorials I published, with the goal of discussing how to prepare your current MySQL instance to be configured as an External Primary Server with a Replica/Follower into Google Cloud Platform.

First, I want to talk about the jargon used here. I will be using primary to represent the external “master” server, and replica to represent the “slave” server. Personally, I prefer the terms leader/follower but primary/replica currently seems to be more common in the industry. At some point, the word slave will be used, but because it is the keyword embedded on the server to represent a replica.

The steps given will be in the context of a VM running a one-click install of …

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A small dive into the MySQL 8.0 X-DevAPI


What is the X-DevApi? From there is a definition of the X-DevAPI and its features in the following paragraphs:

The X DevAPI is the common client-side API used by all connectors to abstract the details of the X Protocol. It specifies the common set of CRUD-style functions/methods used by all the official connectors to work with both document store collections and relational tables, a common expression language to establish query properties such as criteria, projections, aliases, and a standard set of additional database management features for handling things like transactions, indexes, etc.

The fact that most of these features share the same format and API between connectors, makes the X DevAPI a perfect fit for modern polyglot development environments such as microservices, and the fact that they are based on a …

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Using Active Record migrations beyond SQLite

SQLite is really a good tool to set up quick proof of concepts and small applications; however it’s not the most robust solution on the market for working with relational databases. In the open source community two databases take the top of the list: PostgreSQL and MySQL.

I did a small project for my studies. I was using SQLite as I didn’t need much out of it. Curious, I decided to see how the application would behave on other databases and decided to try PostgreSQL and MySQL. I had two problems to solve, and this post is about the first one: how to deal with the migrations. They were as follows:

Active Record automatically put the field id in all of its tables, that’s why it is omitted on the migrations.

In PostgreSQL it …

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From MySQL 8.0.0 to MySQL 8.0.1 – or any other dev milestone

Disclaimer: This post is aimed to you, the curious developer, sys-admin, technologist, whatever-title-you-use. DO NOT run the following lines on production. Not even in a stable environment, do this if you don’t care about the outcome of the current data.

If you want to keep up with the newest MySQL developer milestones I have news for you: there is no upgrade available for milestone versions. The way to go is to remove old version and install new one, according to their website:

Upgrades between milestone releases (or from a milestone release to a GA release) are not supported. For example, upgrading from 8.0.0 to 8.0.1 is not supported, as neither are GA status releases.

So if you, like me, had the 8.0.0 version and want to test the 8.0.1 (alhtough 8.0.3 milestone is already in development) …

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MySQL version poll: a not so scientific analysis

Prior to my talk at LaraconEU 2016 I was curious to know how much adoption for MySQL 5.7 was in within the community.

I tweeted this:

Pool, use twitter client to see it:

Which Version of MySQL do you use? SELECT @VERSION; RT for reach, please.

Gabriela D'Ávila (@gabidavila) August 23, 2016

Twitter polls only gives you up to 4 items to choose. What I wanted to know is if people were using MariaDB or other forks like Percona, but I didn’t had the proper space, and I  only put three options.

This January I managed to get a bit more syndication on my tweet and more people replied. I added a 4th option, “Other”. This option could …

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What MySQL 8.0.1 means to you as a Developer

This post will be updated as soon more information comes along.

This developer version wasn’t released yet, when it does, use at your own risk.

Oracle released the development version of MySQL 8.0.0-dmr on September 12th of 2016. Since then, the team have been working on the 8.0.1 development milestone. You can find the partial change list here.

The objective here is try to explain how this will have any real world impact for you from 8.0.1. Please remember though, that any changes made to this version will not be final until the General Availability (date not currently set).

These topics are aimed at the Software Engineering side and not DBA and this is why Replication, for instance, is not covered …

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Understanding Generated Columns

The Theory

Generated Columns is a feature released on MySQL 5.7. They can be used during CREATE TABLE or ALTER TABLE statements. It is a way of storing data without actually sending it through the INSERT or UPDATE clauses in SQL. The database resolves what the data will be.

There are two types of Generated Columns: Virtual and Stored. They work with:

  • mathematical expressions (product_price * quantity)
  • built-in functions (RIGHT(), CONCAT(), FROM_UNIXTIME(), JSON_EXTRACT())
  • literals (“2”, “new”, 0)

Besides that, they can be indexed but they don’t allow …

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LaraconEU video

This is the video from LaraconEU 2016 on Making the Most out of MySQL.

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