MySQL Skill

Execute MySQL queries and manage databases through a containerized MySQL client.

Overview

This skill provides AI agents with MySQL database access through a Docker-based mysql CLI client. Run queries, manage schemas, export data, and monitor database health.

When to Use This Skill

• Execute SQL queries against MySQL databases
• Manage database schemas and tables
• Export query results
• Monitor database connections and status
• Perform database administration tasks

Prerequisites

• Docker installed and running
• Network access to target MySQL server
• MySQL user credentials with appropriate permissions

Configuration

Add to your .skill-engine.toml:

[skills.mysql]
source = "docker:mysql:8"
runtime = "docker"
description = "MySQL database client"

[skills.mysql.docker]
image = "mysql:8"
entrypoint = "mysql"
network = "bridge"
memory = "256m"
rm = true
environment = [
  "MYSQL_PWD=${MYSQL_PASSWORD}"
]

Configuration Explained

Setting	Value	Description
image	mysql:8	Official MySQL 8 image with mysql client
entrypoint	mysql	Use the mysql command-line client
network	bridge	Bridge network to connect to external databases
memory	256m	Memory limit for the container
rm	true	Auto-remove container after execution

Usage

Arguments after -- are passed directly to the mysql client:

skill run mysql -- [mysql options]

Common Operations

Connect and Run Query

# Simple query
skill run mysql -- -h localhost -u myuser -e "SELECT * FROM users LIMIT 10" mydb

# With explicit password (not recommended - use env var)
skill run mysql -- -h localhost -u myuser -p'password' -e "SHOW DATABASES"

# Using environment variable for password
MYSQL_PASSWORD=secret skill run mysql -- -h localhost -u myuser -e "SHOW TABLES" mydb

List Databases and Tables

# List all databases
skill run mysql -- -h localhost -u root -e "SHOW DATABASES"

# List tables in a database
skill run mysql -- -h localhost -u root -e "SHOW TABLES" mydb

# Describe table structure
skill run mysql -- -h localhost -u root -e "DESCRIBE users" mydb

Data Queries

# Select with conditions
skill run mysql -- -h localhost -u myuser -e "SELECT id, name, email FROM users WHERE active = 1" mydb

# Aggregate query
skill run mysql -- -h localhost -u myuser -e "SELECT status, COUNT(*) as count FROM orders GROUP BY status" mydb

# Join query
skill run mysql -- -h localhost -u myuser -e "SELECT u.name, COUNT(o.id) FROM users u LEFT JOIN orders o ON u.id = o.user_id GROUP BY u.id" mydb

Data Modification

# Insert data
skill run mysql -- -h localhost -u myuser -e "INSERT INTO users (name, email) VALUES ('John', 'john@example.com')" mydb

# Update data
skill run mysql -- -h localhost -u myuser -e "UPDATE users SET active = 0 WHERE last_login < '2024-01-01'" mydb

# Delete data
skill run mysql -- -h localhost -u myuser -e "DELETE FROM sessions WHERE expired_at < NOW()" mydb

Output Formats

# Tab-separated (default)
skill run mysql -- -h localhost -u myuser -e "SELECT * FROM users" mydb

# Vertical format (like \G)
skill run mysql -- -h localhost -u myuser -E -e "SELECT * FROM users LIMIT 1" mydb

# HTML output
skill run mysql -- -h localhost -u myuser -H -e "SELECT * FROM users" mydb

# XML output
skill run mysql -- -h localhost -u myuser -X -e "SELECT * FROM users" mydb

# Skip column names
skill run mysql -- -h localhost -u myuser -N -e "SELECT COUNT(*) FROM users" mydb

Server Information

# Show server status
skill run mysql -- -h localhost -u root -e "SHOW STATUS"

# Show process list
skill run mysql -- -h localhost -u root -e "SHOW PROCESSLIST"

# Show variables
skill run mysql -- -h localhost -u root -e "SHOW VARIABLES LIKE 'max_connections'"

# Show grants
skill run mysql -- -h localhost -u root -e "SHOW GRANTS FOR 'myuser'@'%'"

Schema Management

# Create database
skill run mysql -- -h localhost -u root -e "CREATE DATABASE newdb CHARACTER SET utf8mb4"

# Create table
skill run mysql -- -h localhost -u root -e "CREATE TABLE logs (id INT AUTO_INCREMENT PRIMARY KEY, message TEXT, created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP)" newdb

# Add index
skill run mysql -- -h localhost -u root -e "CREATE INDEX idx_created ON logs(created_at)" newdb

# Alter table
skill run mysql -- -h localhost -u root -e "ALTER TABLE users ADD COLUMN phone VARCHAR(20)" mydb

Advanced Examples

Execute SQL File

# Mount local file and execute
skill run mysql -- -h localhost -u root < /path/to/script.sql mydb

Connect to Remote Database

# Connect to RDS
skill run mysql -- -h mydb.abc123.us-east-1.rds.amazonaws.com -P 3306 -u admin mydb

# Connect with SSL
skill run mysql -- -h secure-db.example.com --ssl-mode=REQUIRED -u myuser mydb

Batch Operations

# Multiple statements
skill run mysql -- -h localhost -u root -e "
  START TRANSACTION;
  INSERT INTO audit_log (action) VALUES ('batch_start');
  UPDATE users SET processed = 1 WHERE processed = 0 LIMIT 100;
  INSERT INTO audit_log (action) VALUES ('batch_end');
  COMMIT;
" mydb

Troubleshooting

Connection Refused

ERROR 2003 (HY000): Can't connect to MySQL server

Solutions:

• Verify the MySQL server is running
• Check host and port are correct
• Ensure network connectivity (container to host)

Access Denied

ERROR 1045 (28000): Access denied for user

Solutions:

• Verify username and password
• Check user has permissions from container's IP
• Use MYSQL_PASSWORD environment variable

Unknown Database

ERROR 1049 (42000): Unknown database 'mydb'

Solution: Verify database name exists: SHOW DATABASES

Common Errors

Error	Cause	Solution
2003	Can't connect	Check host/port/firewall
1045	Access denied	Verify credentials
1049	Unknown database	Check database name
1146	Table doesn't exist	Check table name
2013	Lost connection	Check query timeout

Docker Image Details

Property	Value
Image	mysql:8
Size	~400MB (compressed ~150MB)
Platforms	linux/amd64, linux/arm64
Includes	mysql, mysqldump, mysqlimport, mysqladmin

Security Considerations

• Use environment variables for passwords (MYSQL_PWD)
• Connect over SSL when possible
• Use read-only users for query operations
• Container runs with limited memory
• Network is bridge mode (isolated)

Resources

• MySQL Documentation
• MySQL CLI Reference
• Docker MySQL Image