How to fix ER_ACCESS_DENIED_ERROR: Access denied for user 'username'@'host' (using password: YES/NO) in Node.js

What this error means

Placeholder meaning for ER_ACCESS_DENIED_ERROR: Access denied for user. This error needs detailed documentation.

Typical symptoms

• Symptom 1
• Symptom 2
• Symptom 3

Common causes

1. Cause 1
2. Cause 2
3. Cause 3

How to fix "ER_ACCESS_DENIED_ERROR: Access denied for user 'username'@'host' (using password: YES/NO)"

Advanced notes

Related errors

• Error: EMFILE: too many open files, watch

  EMFILE: fs.watch() limit exceeded

  HIGH

• Error: Middleware next() called multiple times (next() invoked twice)

  Express middleware next() called multiple times

  HIGH

• Error: Worker failed to initialize (worker startup error)

  Worker failed to initialize in Node.js

  HIGH

Official resources & further reading

• 📚Node.js Official Documentation
• 📖
  node-mysql2 GitHub repository - official MySQL driver for Node.js(Official Docs)
• 📖
  node-mysql2 documentation - authentication and connection(Official Docs)
• 🐙
  node-mysql2 authentication issue - unable to authenticate(GitHub)
• 💬
  AWS - Access Denied Error connecting Node.js to MySQL RDS instance(Stack Overflow)