schema.php

<?php
/**
 * This file defines the make_db_sqlite() function.
 *
 * @package SQLite Integration
 * @author Kojima Toshiyasu
 */

if (!defined('ABSPATH')) {
	echo 'Thank you, but you are not allowed to access this file.';
	die();
}
/**
 * Function to create tables according to the schemas of WordPress.
 *
 * This is executed only once while installation.
 *
 * @return boolean
 */
function make_db_sqlite() {
	include_once PDODIR . 'query_create.class.php';
	include_once ABSPATH . 'wp-admin/includes/schema.php';
	$index_array   = array();

	//ob_end_clean();
	$table_schemas = wp_get_db_schema();
	$queries       = explode (";", $table_schemas);
	$query_parser  = new CreateQuery();
	try {
		$pdo = new PDO('sqlite:'.FQDB, null, null, array(PDO::ATTR_ERRMODE => PDO::ERRMODE_EXCEPTION));
	} catch (PDOException $err) {
		$err_data = $err->errorInfo;
		$message  = 'Database connection error!<br />';
		$message .= sprintf("Error message is: %s", $err_data[2]);
		wp_die($message, 'Database Error!');
	}

	try {
		$pdo->beginTransaction();
		foreach ($queries as $query) {
			$query = trim($query);
			if (empty($query))
				continue;
			$rewritten_query = $query_parser->rewrite_query($query);
			if (is_array($rewritten_query)) {
				$table_query   = array_shift($rewritten_query);
				$index_queries = $rewritten_query;
				$table_query   = trim($table_query);
				$pdo->exec($table_query);
				//foreach($rewritten_query as $single_query) {
				//  $single_query = trim($single_query);
				//  $pdo->exec($single_query);
				//}
			} else {
				$rewritten_query = trim($rewritten_query);
				$pdo->exec($rewritten_query);
			}
		}
		$pdo->commit();
		if ($index_queries) {
			// $query_parser rewrites KEY to INDEX, so we don't need KEY pattern
			$pattern = '/CREATE\\s*(UNIQUE\\s*INDEX|INDEX)\\s*IF\\s*NOT\\s*EXISTS\\s*(\\w+)?\\s*.*/im';
			$pdo->beginTransaction();
			foreach ($index_queries as $index_query) {
				preg_match($pattern, $index_query, $match);
				$index_name = trim($match[2]);
				if (in_array($index_name, $index_array)) {
					$r = rand(0, 50);
					$replacement = $index_name . "_$r";
					$index_query = str_ireplace('EXISTS '.$index_name, 'EXISTS '.$replacement, $index_query);
				} else {
					$index_array[] = $index_name;
				}
				$pdo->exec($index_query);
			}
			$pdo->commit();
		}
	} catch (PDOException $err) {
		$err_data = $err->errorInfo;
		$err_code = $err_data[1];
		if (5 == $err_code || 6 == $err_code) {
			// if the database is locked, commit again
			$pdo->commit();
		} else {
			$pdo->rollBack();
			$message  =  sprintf("Error occured while creating tables or indexes...<br />Query was: %s<br />", var_export($rewritten_query, true));
			$message .= sprintf("Error message is: %s", $err_data[2]);
			wp_die($message, 'Database Error!');
		}
	}

	$query_parser = null;
	$pdo   = null;
	return true;
}
?>