MySQL Error 1045 — Access Denied for User

MySQL Error 1045: Access Denied

Error 1045 means MySQL recognized the connection attempt but rejected the authentication. This is the most common MySQL connection error.

Error Format

ERROR 1045 (28000): Access denied for user 'myuser'@'localhost' (using password: YES)

Understanding user@host

MySQL permissions are tied to both the username and the host the client connects from. 'myuser'@'localhost' and 'myuser'@'%' are different accounts.

-- Check existing users
SELECT user, host, plugin FROM mysql.user;

-- Grant access from any host
CREATE USER 'myuser'@'%' IDENTIFIED BY 'password';
GRANT ALL ON mydb.* TO 'myuser'@'%';
FLUSH PRIVILEGES;

Common Causes

1. Wrong password:

-- Reset password
ALTER USER 'myuser'@'localhost' IDENTIFIED BY 'new_password';
FLUSH PRIVILEGES;

2. Authentication plugin mismatch: MySQL 8.0+ defaults to caching_sha2_password, which older clients may not support.

-- Switch to mysql_native_password for compatibility
ALTER USER 'myuser'@'localhost'
IDENTIFIED WITH mysql_native_password BY 'password';

3. Connecting from wrong host: If you created 'myuser'@'localhost' but connect from a Docker container, you are connecting from the container's IP, not localhost.

4. Password in connection string issues: Special characters in passwords (like @, #, %) must be URL-encoded in connection strings:

mysql://user:p%40ssw0rd@host:3306/db

Recovery: Reset Root Password

If you are locked out of root:

# 1. Stop MySQL
sudo systemctl stop mysql

# 2. Start with skip-grant-tables
sudo mysqld_safe --skip-grant-tables &

# 3. Connect without password
mysql -u root

# 4. Reset password
FLUSH PRIVILEGES;
ALTER USER 'root'@'localhost' IDENTIFIED BY 'new_password';

# 5. Restart normally
sudo systemctl restart mysql