Managing Databases

Handle database operations for MySQL and PostgreSQL using direct CLI tools (mysql, psql).

When to Use

• •User asks about MySQL or PostgreSQL operations
• •Database CRUD operations needed
• •SQL query help requested
• •Database connection or credential lookup
• •Table schema inspection or modifications

Quick Start (Credential Discovery)

Before performing any database operation, locate credentials using these methods:

1. Search for Credential Keywords

Search project files for common database credential patterns:

Environment variables:

DB_HOST, DB_USER, DB_PASSWORD, DB_NAME, DB_PORT
DATABASE_URL, DATABASE_HOST, DATABASE_USER
MYSQL_HOST, MYSQL_USER, MYSQL_PASSWORD
POSTGRES_HOST, POSTGRES_USER, POSTGRES_PASSWORD, PGPASSWORD

Connection string patterns:

mysql://user:password@host:port/database
postgresql://user:password@host:port/database
postgres://user:password@host:port/database
sqlite:///path/to/database.db
sqlite:///:memory:

2. Common Credential Locations

Check these files in order:

1. •.env - Primary environment file
2. •.env.local - Local overrides
3. •config/database.yml - Rails/Ruby projects
4. •config/database.php - PHP projects
5. •settings.py or config.py - Python projects
6. •application.properties - Java/Spring projects
7. •docker-compose.yml - Docker environments

3. Validation

• •If credentials found: proceed with CLI commands
• •If credentials missing: STOP and ask the user. DO NOT guess.

Core Workflow

1. •Find Credentials: Search for DB/database keywords and connection strings
2. •Select Tool: Use mysql for MySQL/MariaDB, psql for PostgreSQL
3. •Execute SQL: Use direct CLI execution for simple tasks
4. •Complex Queries: Create a .sql file for multi-step operations

Reference

• •MySQL: See reference/mysql.md - Connection, commands, examples
• •PostgreSQL: See reference/postgresql.md - Connection, commands, examples
• •Examples: See examples.md - Advanced query patterns

Guidelines

• •Escape Strings: Be mindful of escaping to avoid SQL injection
• •Explain First: For UPDATE or DELETE, show the query before execution
• •Backup Warning: Recommend backups before destructive operations

Troubleshooting

• •Connection refused: Verify host/port, check if database service is running
• •Access denied: Double-check username/password, verify user permissions
• •Database not found: Confirm database name exists, check spelling
• •SSL errors: Try adding --ssl-mode=DISABLED (MySQL) or sslmode=disable (PostgreSQL) for local dev