Having trouble connecting to your database during installation? This guide covers common database connection issues and provides step-by-step solutions to fix them.

Issue A: Validation Fails

On Step 1 (Pro) and Step 2 (Lite) of the installer, when you click “Test Database,” you receive a fail status.

Solution 1: Validation Checklist

Ensure that the database credentials and permissions are correctly set up:

• Double-check that the database and database user have been created.
• Verify that the password matches the database user being used.
• Ensure the database user is assigned to the database with the correct permissions.
• Temporarily change the database user password to ‘test123’ to validate character input.
• Contact your hosting provider for the exact required parameters.

Solution 2: Hostname Validation

The default hostname ‘localhost’ works in most cases, but it may differ based on the hosting provider. Confirm the exact settings with your host. Some common variations include:

• mysql.yourname.com
• mysql.hostingcompany.com
• mysql.hostingcompany.com:1400

If you see an error like “Can’t connect to local MySQL server through socket ‘/var/lib/mysql/mysql.sock’ (2),” it is likely due to an incorrect hostname.

Quick Fix:

Contact your hosting provider to confirm the correct credentials for database connections. Refer to these support resources:

• GoDaddy
• HostMonster
• Bluehost
• HostGator
• DreamHost
• Search Google: "[Your host] database setup"

Solution 3: SQL Mode Conflicts

If you encounter an “Error reading database variables” message, your MySQL instance may have “ANSI_QUOTES” enabled in its SQL mode. Since MySQL treats double quotes as identifiers instead of strings in this mode, it can cause issues. To resolve this, remove the ANSI_QUOTES SQL mode.

Common Error Messages:

• Unknown column ‘wp_table’ in ‘where clause’

Issue B: Access Denied

If you receive an error such as Access denied for user 'myuser'@'localhost' (using password: YES) when testing the database connection, follow these solutions.

Common Error Messages:

• Error: 'Access denied; you need (at least one of) the PROCESS privilege ...
• The database user for this WordPress site does NOT have sufficient permissions to write stored procedures ...

Solution 1: Assigning Full Privileges

Ensure that the database user is assigned to the database with full privileges:

• The easiest way to confirm permissions is to contact your hosting provider.
• Follow the WordPress Codex Guide to create a Database and User.
• For a cPanel demo, refer to this article.
• For MySQL 8+: Run the following command to grant all required privileges: GRANT SHOW_ROUTINE ON *.* TO <USER>@<LOCATION>;

Solution 2: Creating a New Database User

If assigning full privileges does not work, create a new database user, grant full permissions, and assign it to the database. This can resolve caching issues stored in the database.

Solution 3: Moving Databases Between Servers

When migrating a site between MySQL servers, different MySQL versions may not support the same directives, leading to an error such as:

• mysqldump: Error: 'Access denied; you need (at least one of) the PROCESS privilege ...'

Workarounds:

• Build in PHP Mode: Use PHP to avoid MySQL directive conflicts.
• Modify SQL Script: Remove unsupported directives from the SQL file before running the installer.

Issue C: Database Timeouts

If SQL connection timeouts or memory errors occur on Step 2, follow these solutions.

Solution 1: Enable Database Chunking

This multi-thread process splits the database installation into smaller queries.

1. Run the installer and activate the Advanced mode by clicking the button “Advanced“
2. In Step 1 Under Options » Database Tab » Processing, enable “Chunking Mode.”
3. Continue with the installation.

Solution 2: Skip Database Extraction

Instead of creating new database tables, manually import the database.

Steps:

1. Extract database.sql from the archive.
2. Use phpMyAdmin to remove existing tables and import the SQL file.
3. In the installer, select “Skip Database Extraction” under Advanced Options.

Solution 3: Duplicator Lite-Specific Issues

Duplicator Lite (v1.4.7.2 or earlier) supports only a single-threaded database import, which can cause issues on busy shared servers.

Workarounds:

• Run the installer during off-peak hours.
• Change the Build Mode in Duplicator settings to “PHP.”
• Contact your host to increase server timeout limits.
• Upgrade to Duplicator Pro to use SQL file chunking.

Common Error Messages:

• MySQL Server has gone away, out of memory, or 500 Error

Troubleshooting

If connection issues persist, use PHP code to isolate the problem. Create a file called db-test.php in the same directory as the installer and insert the following code:

<?php
$servername = "your_server";
$username = "your_username";
$password = "your_password";
$dbname = "your_database";

$conn = new mysqli($servername, $username, $password, $dbname);
if ($conn->connect_error) {
    die("Connection failed: " . $conn->connect_error);
}
echo "Success: Connected to MySQL!";
?>

If the script fails, share it with your hosting provider for further debugging.

This script is also available in the Duplicator Pro tools directory at /plugins/duplicator-pro/tools/db-test.php.

By following these solutions, you can resolve database connection issues and ensure a smooth installation process.