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

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', '[email protected]')" 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

Docker Image Details

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