SQL Error: Connection Refused (Fix + Examples)

Getting the "could not connect to server: Connection refused" error in SQL? This guide explains what causes this error and how to fix it with practical examples.

What Causes This Error?

The connection refused error (08006) occurs when:

• Database server not running
• Wrong host or port configuration
• Firewall blocking connection
• Maximum connections reached
• SSL/TLS configuration mismatch

How to Fix It

1. Verify database server is running: pg_isready or service postgresql status.
2. Check host and port in connection string.
3. Test network connectivity: telnet hostname port.
4. Check pg_hba.conf for allowed connections.
5. Review max_connections setting and current usage.

Example: Wrong vs Correct

❌ Code That Causes the Error

postgresql://user:pass@localhost:5432/db
-- Error: Connection refused if server not running

✅ Corrected Code

# First verify server is running:
pg_isready -h localhost -p 5432
# Then check max connections:
SELECT count(*) FROM pg_stat_activity;

Quick Checklist

• [ ] Verify column/table names are spelled correctly
• [ ] Check data types match expected values
• [ ] Review query syntax for missing keywords
• [ ] Ensure referenced tables/columns exist

Related SQL Errors

If you're troubleshooting SQL errors, you might also encounter: