Database Testing Skill

Specialized skill for testing, debugging, and validating database connectivity and queries.

When to Use

• User reports database connection errors
• Testing a new database configuration
• Validating queries before deployment
• Debugging data retrieval issues
• Verifying authentication configuration

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Steps

Step 1: Network Connectivity Check

# Test if server is reachable
ping <DB_HOST>

# Test database port
# SQL Server: 1433, PostgreSQL: 5432, MySQL: 3306
telnet <DB_HOST> <DB_PORT>

Step 2: Connection String Validation

Check environment configuration:

DB_HOST=<server_name>
DB_NAME=<database_name>
DB_USER=<username>
DB_PASSWORD=<password>
DB_DRIVER=<driver_name>

Step 3: Connection Test

# Generic connection test pattern
import os

try:
    conn = create_connection(
        host=os.getenv("DB_HOST"),
        database=os.getenv("DB_NAME"),
        user=os.getenv("DB_USER"),
        password=os.getenv("DB_PASSWORD"),
    )
    print("Connection successful!")
    cursor = conn.cursor()
    cursor.execute("SELECT 1")
    print(f"Query test: {cursor.fetchone()}")
    conn.close()
except Exception as e:
    print(f"Connection failed: {e}")

Step 4: Query Validation

query = "SELECT TOP 5 * FROM <table_name>"  # Adjust syntax for your DB
df = pd.read_sql(query, conn)
print(f"Returned {len(df)} rows")
print(df.columns.tolist())

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Common Issues & Solutions

Error	Cause	Solution
Connection refused	Server unreachable	Check network/VPN, firewall rules
Login failed	Auth issue	Verify credentials, check auth mode
Invalid connection string	Malformed config	Review driver docs for correct format
Certificate error	SSL validation	Configure trust settings for your DB
Driver not found	Missing driver	Install appropriate database driver

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Output Format

## Database Connection Test Results

**Server**: `<server>`
**Database**: `<database>`
**Auth Mode**: <auth_type>

| Test | Status | Details |
|------|--------|---------|
| Network ping | Pass/Fail | Response time |
| Port check | Pass/Fail | TCP connection |
| DB connection | Pass/Fail | Driver info |
| Sample query | Pass/Fail | Row count |

**Conclusion**: [Summary]

Checklist

• Network connectivity verified
• Connection string validated
• Authentication working
• Sample query returns expected results
• Error handling tested
• Connection cleanup (close/dispose) confirmed