287 posts tagged with "MySQL"

The character set decides which characters MySQL can store, and the collation decides how it compares and sorts them. Get them wrong and emoji fail to save, or café and cafe turn out to be "equal" when you didn't expect it. This guide checks both at the server, database and connection level, and proves what the default utf8mb4_0900_ai_ci really does.

Before you follow a guide, report a bug or plan an upgrade, you need to know exactly which MySQL you're talking to. MySQL tells you in several places, and one of them works without signing in at all. This guide shows five ways, with real output from MySQL 9.7.4 in Docker, and the one place where the version you see can mislead you.

The official MySQL Docker image already contains the mysql command-line client, so you don't need to install anything on your computer to run SQL. One docker compose exec command opens the client inside the running container. This guide signs in, runs the first few queries every new database deserves, and shows the small things that confuse beginners.

You don't need to install MySQL to use it. With Docker Desktop, one small compose.yaml file runs the official MySQL 9.7 image with its data stored safely in a volume, and one command starts it. This guide builds that file line by line, starts MySQL for the first time, and shows exactly what to look for in the output.

I ran SHOW PROCESSLIST in MySQL 9.7 to see who was connected, and the result ended with 1 warning. SHOW WARNINGS named it: Warning 1287, the old implementation behind SHOW PROCESSLIST is deprecated. Querying the Performance Schema's processlist table directly gives the same list, without the warning.

I changed a password in my .env file, restarted MySQL with Docker Compose, and MySQL rejected the new password with ERROR 1045 (28000): Access denied. The container had the new value, but MySQL was still expecting the old one. This post shows why that happens with the official MySQL image, and how I fixed it without deleting any data.

I typed SELECT 'café' into the mysql client inside the official MySQL Docker container, and the client showed 'caf'. The é never appeared on screen and never reached MySQL, and there was no error at all. The container runs without a locale, so the client only accepts plain ASCII. One extra flag on docker compose exec fixes it.