Snippets about sql

Create a database user in MariaDB

One user per application, with only the rights it needs.

Update a table from another table

Copy values across tables with a join, in MySQL, MariaDB and PostgreSQL.

Upsert in PostgreSQL

Insert a row, or update it if it already exists, in one statement.

Tunnel to a remote database over SSH

Use your local database tools on a server's database that isn't exposed to the internet.

Delete duplicate rows but keep one

Clean up a table after finding the duplicates, keeping the oldest of each.

Latest row per group in SQL

The newest order of every customer, in one query.

MariaDB in Docker for local development

A database for the project that you can throw away and recreate in a second.

Dump and restore a MariaDB database

Backups, moving a database to another server, or copying production to your machine.

Find duplicate rows in SQL

Which emails are in the users table more than once?

Concat IDs into a single field in SQL

Here is how to merge multiple SQL rows into one, values separated by a comma.