MySQL Error 1045 - Access Denied

What It Means

MySQL error 1045 (ER_ACCESS_DENIED_ERROR) means “Access denied for user ‘username’@‘host’ (using password: YES/NO).” The MySQL server rejected the connection because the credentials are invalid, the user does not exist for the connecting host, or the user lacks the required privileges.

Common Causes

• Wrong username or password
• User exists but not for the connecting host (e.g., 'user'@'localhost' vs 'user'@'%')
• Password was recently changed
• Connecting without a password when one is required
• User account is locked
• Authentication plugin mismatch (e.g., caching_sha2_password vs mysql_native_password)
• Environment variable with password has trailing whitespace or quotes

How to Fix

Verify credentials

# Test connection with explicit credentials
mysql -u root -p -h 127.0.0.1

# Check if the user exists
mysql -u root -p -e "SELECT user, host, plugin FROM mysql.user;"

Reset root password

# Stop MySQL
sudo systemctl stop mysql

# Start in safe mode
sudo mysqld_safe --skip-grant-tables &

# Connect without password
mysql -u root

# Reset the password
ALTER USER 'root'@'localhost' IDENTIFIED BY 'NewPassword123!';
FLUSH PRIVILEGES;

# Restart MySQL normally
sudo systemctl restart mysql

Create or fix user access

-- Create a user for specific host
CREATE USER 'myapp'@'localhost' IDENTIFIED BY 'secure_password';
GRANT ALL PRIVILEGES ON mydb.* TO 'myapp'@'localhost';

-- Create a user for any host
CREATE USER 'myapp'@'%' IDENTIFIED BY 'secure_password';
GRANT ALL PRIVILEGES ON mydb.* TO 'myapp'@'%';

FLUSH PRIVILEGES;

-- Check existing grants
SHOW GRANTS FOR 'myapp'@'localhost';

Fix authentication plugin issues

-- MySQL 8.0+ uses caching_sha2_password by default
-- If your client doesn't support it, switch to mysql_native_password
ALTER USER 'myapp'@'localhost' IDENTIFIED WITH mysql_native_password BY 'password';
FLUSH PRIVILEGES;

Fix in application code

// Node.js with mysql2
const mysql = require('mysql2');
const connection = mysql.createConnection({
  host: '127.0.0.1',  // Use IP instead of 'localhost' to force TCP
  user: 'myapp',
  password: process.env.DB_PASSWORD,  // Check for trailing whitespace!
  database: 'mydb'
});

# Python with mysql-connector
import mysql.connector

connection = mysql.connector.connect(
    host='127.0.0.1',
    user='myapp',
    password='secure_password',
    database='mydb',
    auth_plugin='mysql_native_password'  # If needed
)

Docker MySQL access

# Docker: ensure MYSQL_ROOT_PASSWORD matches
docker run -e MYSQL_ROOT_PASSWORD=rootpass \
           -e MYSQL_USER=myapp \
           -e MYSQL_PASSWORD=apppass \
           -e MYSQL_DATABASE=mydb \
           mysql:8.0

Related Errors

• MySQL 1049 - Unknown database: Authenticated but the database doesn’t exist.
• MySQL 2002 - Connection refused: Cannot connect to the MySQL socket.
• MySQL 2003 - Can’t connect: Cannot reach the MySQL server.