### Initialize and Start WP MySQL Proxy in PHP

Source: https://github.com/wordpress/sqlite-database-integration/blob/develop/packages/wp-mysql-proxy/README.md

This PHP code snippet demonstrates how to instantiate and start the WP MySQL Proxy. It requires the `MySQL_Proxy` class and a specific adapter, such as `SQLite_Adapter`. Configuration options like the database path, port, and log level can be passed during initialization.

```php
use WP_MySQL_Proxy\MySQL_Proxy;
use WP_MySQL_Proxy\Adapter\SQLite_Adapter;

require_once __DIR__ . '/vendor/autoload.php';

$proxy = new MySQL_Proxy(
	new SQLite_Adapter( $db_path ),
	array( 'port' => $port, 'log_level' => $log_level )
);
$proxy->start();
```

--------------------------------

### Activate SQLite Drop-in for WordPress

Source: https://context7.com/wordpress/sqlite-database-integration/llms.txt

This PHP code demonstrates the process of activating the SQLite database integration by installing the `db.php` drop-in file. It includes checks for the PDO SQLite extension and verifies the installation. WordPress automatically loads `wp-content/db.php` on startup to override the default database driver.

```php
<?php
/**
 * Activate SQLite integration by installing the database drop-in.
 * This copies the db.php file to wp-content/db.php, which WordPress
 * automatically loads to override the default MySQL database driver.
 */

// Trigger activation after plugin is activated
function my_sqlite_activation_handler() {
    // Check if PDO SQLite extension is available
    if (!extension_loaded('pdo_sqlite')) {
        wp_die('PDO SQLite extension is not loaded. Please enable it in your PHP configuration.');
    }

    // The plugin handles this automatically via sqlite_plugin_copy_db_file()
    // which is called in activate.php. No manual intervention needed.

    // After activation, the drop-in is installed at:
    // WP_CONTENT_DIR . '/db.php'

    // The plugin automatically redirects to:
    $admin_url = admin_url('options-general.php?page=sqlite-integration');

    // Verify installation
    if (defined('SQLITE_DB_DROPIN_VERSION')) {
        echo 'SQLite is now active!';
    }
}

// Example: Check if SQLite is currently active
if (defined('DB_ENGINE') && DB_ENGINE === 'sqlite') {
    echo 'Running on SQLite';
    echo 'Database file: ' . FQDB; // e.g., /path/to/wp-content/database/.ht.sqlite
} else {
    echo 'Running on MySQL/MariaDB';
}

```

--------------------------------

### Start WP MySQL Proxy via CLI

Source: https://github.com/wordpress/sqlite-database-integration/blob/develop/packages/wp-mysql-proxy/README.md

This command starts the WP MySQL Proxy from the command line. It allows specifying the listening port, the path to the SQLite database file, and the log level for the proxy's operations. Default values are provided for port (3306), database (:memory:), and log level (info).

```bash
php bin/wp-mysql-proxy.php [--port <port>] [--database <path/to/db.sqlite>] [--log-level <log_level>]

Options:
  -h, --help              Show this help message and exit.
  -p, --port=<port>       The port to listen on. Default: 3306
  -d, --database=<path>   The path to the SQLite database file. Default: :memory:
  -l, --log-level=<level> The log level to use. One of 'error', 'warning', 'info', 'debug'. Default: info
```

--------------------------------

### Configure WordPress SQLite Database via wp-config.php

Source: https://context7.com/wordpress/sqlite-database-integration/llms.txt

This snippet outlines how to customize SQLite database settings for WordPress by adding constants to the wp-config.php file. It covers specifying the database engine, custom directory, filename, and database name. These configurations ensure the database is correctly located and identified upon installation or runtime.

```php
<?php
/**
 * Add these constants to wp-config.php to customize SQLite behavior.
 * Place them before the "That's all, stop editing!" line.
 */

// Specify SQLite as the database engine
define('DB_ENGINE', 'sqlite');

// Custom database directory (default: wp-content/database/)
define('DB_DIR', '/var/www/secure-data/');

// Custom database filename (default: .ht.sqlite)
define('DB_FILE', 'wordpress.db');

// The full path is automatically constructed
// FQDB will be: /var/www/secure-data/wordpress.db

// Set database name (required for new installations)
define('DB_NAME', 'my_wordpress_site');

// Enable AST driver via environment variable (optional)
// Set in .env or server configuration
// WP_SQLITE_AST_DRIVER=true

// Journal mode can be set via constant (if supported in future versions)
// For now, it's set during connection initialization

// Example complete wp-config.php configuration:
/*
define('DB_ENGINE', 'sqlite');
define('DB_NAME', 'wordpress_production');
define('DB_DIR', '/secure/databases/');
define('DB_FILE', 'wp_prod.sqlite');

// Standard WordPress configuration continues...
define('DB_CHARSET', 'utf8mb4'); // Handled by SQLite internally
define('DB_COLLATE', ''); // Not used with SQLite
define('AUTH_KEY', 'your-key-here');
// ... rest of wp-config.php
*/

// Verify configuration
if (file_exists(FQDB)) {
    echo 'Database location: ' . FQDB . "\n";
    echo 'Database size: ' . size_format(filesize(FQDB)) . "\n";
} else {
    echo 'Database will be created at: ' . FQDB;
}

```

--------------------------------

### Execute MySQL Queries on SQLite with WP_PDO_MySQL_On_SQLite

Source: https://context7.com/wordpress/sqlite-database-integration/llms.txt

This snippet demonstrates how to initialize and use the WP_PDO_MySQL_On_SQLite driver to execute various MySQL queries against an SQLite database. It covers SELECT, INSERT with ON DUPLICATE KEY UPDATE, transaction management, and retrieving driver information. Dependencies include the WP_SQLite_Connection class.

```php
<?php
/**
 * Execute MySQL queries on SQLite with automatic translation.
 * This is the core driver that emulates MySQL behavior on SQLite.
 */

// Initialize the MySQL-on-SQLite driver
$connection = new WP_SQLite_Connection([
    'path' => FQDB,
    'journal_mode' => 'WAL'
]);

$driver = new WP_PDO_MySQL_On_SQLite(
    $connection,
    'wordpress_db', // Database name
    80038 // MySQL version to emulate (8.0.38)
);

// Execute a MySQL SELECT query
$result = $driver->query('SELECT * FROM wp_posts WHERE post_status = "publish" LIMIT 10');
while ($row = $result->fetch(PDO::FETCH_ASSOC)) {
    echo $row['post_title'] . "\n";
}

// Execute MySQL INSERT with ON DUPLICATE KEY UPDATE
$insert_query = "
    INSERT INTO wp_options (option_name, option_value, autoload)
    VALUES ('site_url', 'https://example.com', 'yes')
    ON DUPLICATE KEY UPDATE option_value = VALUES(option_value)
";
$driver->query($insert_query);

// Transaction management (MySQL-compatible API)
$driver->beginTransaction();
try {
    $driver->query("INSERT INTO wp_posts (post_title, post_status) VALUES ('Test', 'draft')");
    $driver->query("UPDATE wp_posts SET post_status = 'publish' WHERE post_title = 'Test'");
    $driver->commit();
} catch (Exception $e) {
    $driver->rollBack();
    error_log('Transaction failed: ' . $e->getMessage());
}

// Check transaction status
if ($driver->inTransaction()) {
    echo 'Transaction is active';
}

// Get database version information
$sqlite_version = $driver->get_sqlite_version(); // e.g., "3.37.0"
$driver_version = $driver->get_saved_driver_version(); // e.g., "2.2.15"

// Access the connection
$connection = $driver->get_connection();

```

--------------------------------

### PHP: MySQL LIKE Pattern Matching Translation for SQLite

Source: https://context7.com/wordpress/sqlite-database-integration/llms.txt

Explains how MySQL's LIKE operator with wildcard characters is handled by the plugin for SQLite. This facilitates searching for text patterns within string columns.

```php
<?php
// LIKE pattern matching with wildcards
$search = $wpdb->get_results($wpdb->prepare("
    SELECT post_title
    FROM {$wpdb->posts}
    WHERE post_title LIKE %s
    OR post_content LIKE %s
", '%wordpress%', '%plugin%'));

```

--------------------------------

### MySQL to SQLite Data Type Translation in WP_PDO_MySQL_On_SQLite

Source: https://context7.com/wordpress/sqlite-database-integration/llms.txt

This snippet illustrates the automatic data type translation from MySQL to SQLite performed by the driver. It shows a MySQL CREATE TABLE statement and lists the corresponding SQLite type mappings. The driver also handles MySQL-specific directives gracefully. Input is a MySQL CREATE TABLE statement.

```php
<?php
/**
 * MySQL data types are automatically translated to SQLite equivalents.
 * The driver maintains metadata to preserve MySQL-specific type information.
 */

// MySQL CREATE TABLE statement
$create_table = "
    CREATE TABLE wp_custom_data (
        id BIGINT UNSIGNED AUTO_INCREMENT PRIMARY KEY,
        name VARCHAR(255) NOT NULL,
        age TINYINT,
        price DECIMAL(10,2),
        created_at DATETIME DEFAULT CURRENT_TIMESTAMP,
        is_active BOOLEAN DEFAULT 1,
        description TEXT,
        metadata JSON,
        avatar BLOB
    ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci
";

// Automatically translated to SQLite:
// - BIGINT → INTEGER
// - VARCHAR(255) → TEXT
// - TINYINT → INTEGER
// - DECIMAL(10,2) → REAL
// - DATETIME → TEXT
// - BOOLEAN → INTEGER
// - TEXT → TEXT
// - JSON → TEXT
// - BLOB → BLOB
// - AUTO_INCREMENT is handled via SQLite's AUTOINCREMENT
// - InnoDB, CHARSET, COLLATE directives are handled gracefully

$driver->query($create_table);

// Insert data using MySQL syntax
$insert = "
    INSERT INTO wp_custom_data
    (name, age, price, is_active, description, metadata)
    VALUES
    ('John Doe', 30, 99.99, TRUE, 'Test user', '{\"role\":\"admin\"}')
";
$driver->query($insert);

// Query with MySQL functions - automatically translated
$select = "
    SELECT
        id,
        name,
        DATE_FORMAT(created_at, '%Y-%m-%d') as date,
        CONCAT(name, ' (', age, ')') as name_age,
        IFNULL(description, 'No description') as desc
    FROM wp_custom_data
    WHERE age BETWEEN 25 AND 35
";
$result = $driver->query($select);

```

--------------------------------

### WordPress Standard $wpdb Operations with SQLite

Source: https://context7.com/wordpress/sqlite-database-integration/llms.txt

This snippet shows how standard WordPress database operations using the global $wpdb object work seamlessly with SQLite. It covers fetching posts, user data, inserting options, updating posts, and performing complex queries with JOINs. Dependencies include the WordPress environment and SQLite configured as the database engine.

```php
<?php
/**
 * Once the plugin is activated, all WordPress database operations
 * automatically use SQLite through the $wpdb global object.
 */

global $wpdb;

// Standard $wpdb operations work unchanged
$posts = $wpdb->get_results(
    "SELECT ID, post_title, post_date
    FROM {$wpdb->posts}
    WHERE post_status = 'publish'
    ORDER BY post_date DESC
    LIMIT 5
");

foreach ($posts as $post) {
    echo $post->post_title . ' - ' . $post->post_date . "\n";
}

// Prepared statements work as expected
$user_id = 1;
$user = $wpdb->get_row($wpdb->prepare(
    "SELECT * FROM {$wpdb->users} WHERE ID = %d",
    $user_id
));

// Insert with MySQL syntax
$wpdb->insert(
    $wpdb->prefix . 'options',
    [
        'option_name' => 'my_custom_option',
        'option_value' => 'custom_value',
        'autoload' => 'yes'
    ],
    ['%s', '%s', '%s']
);

// Update operations
$wpdb->update(
    $wpdb->posts,
    ['post_status' => 'publish'],
    ['ID' => 123],
    ['%s'],
    ['%d']
);

// Complex queries with JOINs
$results = $wpdb->get_results(
    "SELECT p.*, pm.meta_value as custom_field
    FROM {$wpdb->posts} p
    LEFT JOIN {$wpdb->postmeta} pm ON p.ID = pm.post_id AND pm.meta_key = '_thumbnail_id'
    WHERE p.post_type = 'post'
    AND p.post_status = 'publish'
");

// Check database engine
if (defined('DB_ENGINE') && DB_ENGINE === 'sqlite') {
    // SQLite-specific optimizations
    $db_file_size = filesize(FQDB);
    echo 'Database size: ' . size_format($db_file_size);
}

```

--------------------------------

### WordPress SQLite Query Monitoring and Debugging

Source: https://context7.com/wordpress/sqlite-database-integration/llms.txt

This PHP code snippet shows how to enable and utilize debugging features for SQLite in WordPress. It configures WordPress for debugging, integrates with the Query Monitor plugin for detailed analysis, and accesses internal translator logs for debugging translated queries. It also includes basic performance monitoring for query execution.

```php
<?php
/**
 * The plugin integrates with Query Monitor plugin for detailed query analysis.
 * It also provides internal debugging capabilities.
 */

// Enable WordPress debugging in wp-config.php
define('WP_DEBUG', true);
define('WP_DEBUG_LOG', true);
define('SAVEQUERIES', true);

// Install and activate Query Monitor plugin alongside SQLite Integration
// The plugins work together seamlessly - SQLite plugin detects Query Monitor

// Access query log through $wpdb
global $wpdb;

// View all executed queries
if (defined('SAVEQUERIES') && SAVEQUERIES) {
    foreach ($wpdb->queries as $query) {
        list($sql, $time, $stack) = $query;
        echo "Query: {$sql}\n";
        echo "Time: {$time} seconds\n";
        echo "Called by: {$stack}\n\n";
    }
}

// The WP_SQLite_Translator class logs translated queries
// Access through driver internals (not recommended for production)
global $wpdb;
if (method_exists($wpdb, 'get_translator')) {
    $translator = $wpdb->get_translator();

    // Last MySQL query
    echo "Original MySQL: " . $translator->mysql_query . "\n";

    // Executed SQLite queries
    foreach ($translator->executed_sqlite_queries as $sqlite_query) {
        echo "SQLite: " . $sqlite_query . "\n";
    }
}

// Performance monitoring
$start_time = microtime(true);

// Execute queries
$posts = $wpdb->get_results("SELECT * FROM {$wpdb->posts} WHERE post_status = 'publish'");

$end_time = microtime(true);
$execution_time = $end_time - $start_time;

echo "Query executed in: " . $execution_time . " seconds\n";
echo "Number of queries: " . $wpdb->num_queries . "\n";
echo "Last query: " . $wpdb->last_query . "\n";
echo "Last error: " . $wpdb->last_error . "\n";

```

--------------------------------

### PHP: MySQL Aggregate Function Translation to SQLite Equivalents

Source: https://context7.com/wordpress/sqlite-database-integration/llms.txt

Shows the translation of MySQL aggregate functions such as COUNT(), SUM(), AVG(), MIN(), and MAX() to SQLite. This enables performing calculations and summaries on data sets within database queries.

```php
<?php
// Aggregate functions - COUNT(), SUM(), AVG(), MIN(), MAX()
$stats = $wpdb->get_row("
    SELECT
        COUNT(*) as total_posts,
        COUNT(DISTINCT post_author) as unique_authors,
        AVG(comment_count) as avg_comments,
        MAX(post_date) as latest_post
    FROM {$wpdb->posts}
    WHERE post_status = 'publish'
");

```

--------------------------------

### WordPress SQLite Admin Page and Site Health Integration

Source: https://context7.com/wordpress/sqlite-database-integration/llms.txt

This PHP code snippet demonstrates how to integrate SQLite with WordPress. It includes creating an admin settings page, checking SQLite status, and integrating with WordPress Site Health to display database-specific information. It also includes a check for the PDO SQLite extension and handles deactivation by reverting to MySQL.

```php
<?php
/**
 * The plugin adds an admin page at Settings > SQLite Integration
 * and integrates with WordPress Site Health.
 */

// Check if SQLite is active programmatically
if (defined('SQLITE_DB_DROPIN_VERSION')) {
    echo 'SQLite is enabled. Drop-in version: ' . SQLITE_DB_DROPIN_VERSION;
}

// Access admin page URL
$settings_url = admin_url('options-general.php?page=sqlite-integration');

// Site Health integration - filter debug data
add_filter('debug_information', function($info) {
    // Check current database engine
    $db_engine = defined('DB_ENGINE') && DB_ENGINE === 'sqlite' ? 'sqlite' : 'mysql';

    if ($db_engine === 'sqlite') {
        // Add SQLite-specific information
        $info['wp-database']['fields']['database_type'] = [
            'label' => 'Database Type',
            'value' => 'SQLite'
        ];

        $info['wp-database']['fields']['database_file'] = [
            'label' => 'Database File',
            'value' => FQDB,
            'private' => true
        ];

        $info['wp-database']['fields']['database_size'] = [
            'label' => 'Database Size',
            'value' => size_format(filesize(FQDB))
        ];
    }

    return $info;
}, 10);

// Check PDO SQLite availability
if (!extension_loaded('pdo_sqlite')) {
    add_action('admin_notices', function() {
        echo '<div class="notice notice-error"><p>';
        echo 'PDO SQLite extension is not loaded. Please enable it in php.ini';
        echo '</p></div>';
    });
}

// Deactivation - removes the drop-in
function my_check_before_deactivation() {
    if (defined('SQLITE_DB_DROPIN_VERSION')) {
        // Plugin will automatically remove wp-content/db.php on deactivation
        // This reverts to MySQL if it was configured previously
        error_log('Switching from SQLite back to MySQL');
    }
}
register_deactivation_hook(__FILE__, 'my_check_before_deactivation');

```

--------------------------------

### PHP: MySQL Operators Translation for SQLite (BETWEEN, IN)

Source: https://context7.com/wordpress/sqlite-database-integration/llms.txt

Illustrates the translation of common MySQL operators like BETWEEN and IN for use with SQLite. This allows for efficient range and list-based filtering of records.

```php
<?php
// BETWEEN, IN, and other operators
$wpdb->get_results("
    SELECT * FROM {$wpdb->posts}
    WHERE post_date BETWEEN '2024-01-01' AND '2024-12-31'
    AND post_status IN ('publish', 'future')
    AND comment_count > 0
    ORDER BY post_date DESC
");

```

--------------------------------

### PHP: MySQL String Function Translation to SQLite Equivalents

Source: https://context7.com/wordpress/sqlite-database-integration/llms.txt

Illustrates the translation of MySQL string manipulation functions like CONCAT(), SUBSTRING(), LENGTH(), and UPPER() to their SQLite counterparts. This enables combining, truncating, measuring, and case-changing strings within queries.

```php
<?php
// String functions - CONCAT(), SUBSTRING(), LENGTH()
$wpdb->get_results("
    SELECT
        CONCAT(post_title, ' - ', post_name) as full_name,
        SUBSTRING(post_content, 1, 100) as excerpt,
        LENGTH(post_content) as content_length,
        UPPER(post_status) as status_upper
    FROM {$wpdb->posts}
");

```

--------------------------------

### PHP: MySQL Conditional Function Translation to SQLite IF, IFNULL, COALESCE

Source: https://context7.com/wordpress/sqlite-database-integration/llms.txt

Demonstrates how MySQL's conditional functions IF(), IFNULL(), and COALESCE() are translated for SQLite. This allows for logic within queries, handling null values, and providing default values.

```php
<?php
// Conditional functions - IF(), IFNULL(), COALESCE()
$wpdb->get_results("
    SELECT
        post_title,
        IF(comment_count > 0, 'Has Comments', 'No Comments') as comment_status,
        IFNULL(post_excerpt, post_content) as display_text,
        COALESCE(post_modified, post_date, NOW()) as last_change
    FROM {$wpdb->posts}
");

```

--------------------------------

### WP_SQLite_Connection - SQLite Database Connection Management

Source: https://context7.com/wordpress/sqlite-database-integration/llms.txt

This PHP class manages SQLite database connections, allowing configuration of the database file path, connection timeouts, and journal modes for performance tuning. It also supports using an existing PDO instance and executing raw SQLite queries.

```php
<?php
/**
 * Initialize an SQLite connection with custom configuration.
 * This class encapsulates PDO connection management and SQLite-specific settings.
 */

// Basic connection to SQLite database file
$connection = new WP_SQLite_Connection([
    'path' => '/var/www/html/wp-content/database/.ht.sqlite',
    'timeout' => 10, // Seconds to wait for writable lock
    'journal_mode' => 'WAL' // Write-Ahead Logging for better concurrency
]);

// In-memory database for testing
$memory_connection = new WP_SQLite_Connection([
    'path' => ':memory:',
    'timeout' => 5
]);

// Using existing PDO instance
$pdo = new PDO('sqlite:/path/to/database.db');
$connection = new WP_SQLite_Connection([
    'pdo' => $pdo,
    'journal_mode' => 'DELETE'
]);

// Available journal modes for performance tuning:
// - 'DELETE': Default, deletes journal file after commit
// - 'TRUNCATE': Truncates journal instead of deleting
// - 'PERSIST': Keeps journal file, just zeros header
// - 'MEMORY': Stores journal in memory (faster but less safe)
// - 'WAL': Write-Ahead Logging (best for concurrent reads/writes)
// - 'OFF': No journal (dangerous, fastest)

// Get underlying PDO instance
$pdo = $connection->get_pdo();

// Execute raw SQLite queries
$connection->query('PRAGMA foreign_keys = ON');

```

--------------------------------

### PHP: MySQL Date Format Translation to SQLite strftime

Source: https://context7.com/wordpress/sqlite-database-integration/llms.txt

Shows how the plugin translates MySQL's DATE_FORMAT() function to SQLite's strftime() for custom date output. This is useful for displaying dates in various formats directly from the database query.

```php
<?php
/**
 * The plugin translates MySQL-specific functions to SQLite equivalents.
 * These examples show MySQL syntax that works seamlessly with SQLite.
 */

global $wpdb;

// Date formatting - DATE_FORMAT() translated to strftime()
$results = $wpdb->get_results("
    SELECT
        post_title,
        DATE_FORMAT(post_date, '%Y-%m-%d') as formatted_date,
        DATE_FORMAT(post_date, '%W, %M %d, %Y') as long_date
    FROM {$wpdb->posts}
    WHERE post_status = 'publish'
");

```

=== COMPLETE CONTENT === This response contains all available snippets from this library. No additional content exists. Do not make further requests.