.
*/
namespace Fisharebest\Webtrees;
use Fisharebest\Webtrees\Schema\MigrationInterface;
use PDO;
use PDOException;
/**
* Extend PHP's native PDO class.
*/
class Database {
/** @var Database Implement the singleton pattern */
private static $instance;
/** @var PDO Native PHP database driver */
private static $pdo;
/** @var array Keep a log of all the SQL statements that we execute */
private static $log;
/** @var Statement[] Cache of prepared statements */
private static $prepared = [];
/**
* Prevent instantiation via new Database
*/
private function __construct() {
self::$log = [];
}
/**
* Begin a transaction.
*
* @return bool
*/
public static function beginTransaction() {
return self::$pdo->beginTransaction();
}
/**
* Commit this transaction.
*
* @return bool
*/
public static function commit() {
return self::$pdo->commit();
}
/**
* Disconnect from the server, so we can connect to another one
*/
public static function disconnect() {
self::$pdo = null;
}
/**
* Implement the singleton pattern, using a static accessor.
*
* @param string $DBHOST
* @param string $DBPORT
* @param string $DBNAME
* @param string $DBUSER
* @param string $DBPASS
*
* @throws \Exception
*/
public static function createInstance($DBHOST, $DBPORT, $DBNAME, $DBUSER, $DBPASS) {
if (self::$pdo instanceof PDO) {
throw new \Exception('Database::createInstance() can only be called once.');
}
// Create the underlying PDO object
self::$pdo = new PDO(
(substr($DBHOST, 0, 1) === '/' ?
"mysql:unix_socket={$DBHOST};dbname={$DBNAME}" :
"mysql:host={$DBHOST};dbname={$DBNAME};port={$DBPORT}"
),
$DBUSER, $DBPASS,
[
PDO::ATTR_ERRMODE => PDO::ERRMODE_EXCEPTION,
PDO::ATTR_DEFAULT_FETCH_MODE => PDO::FETCH_OBJ,
PDO::ATTR_CASE => PDO::CASE_LOWER,
PDO::ATTR_AUTOCOMMIT => true,
]
);
self::$pdo->exec("SET NAMES UTF8");
self::$pdo->prepare("SET time_zone = :time_zone")->execute(['time_zone' => date('P')]);
self::$instance = new self;
}
/**
* We don't access $instance directly, only via query(), exec() and prepare()
*
* @throws \Exception
*
* @return Database
*/
public static function getInstance() {
if (self::$pdo instanceof PDO) {
return self::$instance;
} else {
throw new \Exception('createInstance() must be called before getInstance().');
}
}
/**
* Are we currently connected to a database?
*
* @return bool
*/
public static function isConnected() {
return self::$pdo instanceof PDO;
}
/**
* Log the details of a query, for debugging and analysis.
*
* @param string $query
* @param int $rows
* @param float $microseconds
* @param string[] $bind_variables
*/
public static function logQuery($query, $rows, $microseconds, $bind_variables) {
// Trace
$trace = debug_backtrace();
array_shift($trace);
array_shift($trace);
foreach ($trace as $n => $frame) {
if (isset($frame['file']) && isset($frame['line'])) {
$trace[$n] = basename($frame['file']) . ':' . $frame['line'] . ' ' . $frame['function'];
} else {
unset($trace[$n]);
}
}
$stack = '' . (count(self::$log) + 1) . '';
// Bind variables
foreach ($bind_variables as $key => $value) {
if (is_null($value)) {
$value = 'NULL';
} elseif (!is_integer($value)) {
$value = '\'' . $value . '\'';
}
if (is_integer($key)) {
$query = preg_replace('/\?/', $value, $query, 1);
} else {
$query = str_replace(':' . $key, $value, $query);
}
}
$milliseconds = sprintf('%.3f', $microseconds * 1000);
self::$log[] = '| ' .$stack . ' | ' . $query . ' | ' . $rows . ' | ' . $milliseconds . ' |
';
}
/**
* Determine the number of queries executed, for the page statistics.
*
* @return int
*/
public static function getQueryCount() {
return count(self::$log);
}
/**
* Convert the query log into an HTML table.
*
* @return string
*/
public static function getQueryLog() {
$html = '| # | Query | Rows | Time (ms) |
|---|
' . implode('', self::$log) . '
';
self::$log = [];
return $html;
}
/**
* Determine the most recently created value of an AUTO_INCREMENT field.
*
* @return string
*/
public static function lastInsertId() {
return self::$pdo->lastInsertId();
}
/**
* Quote a string for embedding in a MySQL statement.
*
* The native quote() function does not convert PHP nulls to DB nulls
*
* @param string $string
*
* @return string
*
* @deprecated We should use bind-variables instead.
*/
public static function quote($string) {
if (is_null($string)) {
return 'NULL';
} else {
return self::$pdo->quote($string, PDO::PARAM_STR);
}
}
/**
* Execute an SQL statement, and log the result.
*
* @param string $sql The SQL statement to execute
*
* @return int The number of rows affected by this SQL query
*/
public static function exec($sql) {
$sql = str_replace('##', WT_TBLPREFIX, $sql);
$start = microtime(true);
$rows = self::$pdo->exec($sql);
$end = microtime(true);
self::logQuery($sql, $rows, $end - $start, []);
return $rows;
}
/**
* Prepare an SQL statement for execution.
*
* @param $sql
*
* @throws \Exception
*
* @return Statement
*/
public static function prepare($sql) {
if (!self::$pdo instanceof PDO) {
throw new \Exception('No Connection Established');
}
$sql = str_replace('##', WT_TBLPREFIX, $sql);
$hash = md5($sql);
if (!array_key_exists($hash, self::$prepared)) {
self::$prepared[$hash] = new Statement(self::$pdo->prepare($sql));
}
return self::$prepared[$hash];
}
/**
* Roll back this transaction.
*
* @return bool
*/
public static function rollBack() {
return self::$pdo->rollBack();
}
/**
* Run a series of scripts to bring the database schema up to date.
*
* @param string $namespace Where to find our MigrationXXX classes
* @param string $schema_name Where to find our MigrationXXX classes
* @param int $target_version updade/downgrade to this version
*
* @throws PDOException
*
* @return bool Were any updates applied
*/
public static function updateSchema($namespace, $schema_name, $target_version) {
try {
$current_version = (int) Site::getPreference($schema_name);
} catch (PDOException $e) {
// During initial installation, the site_preference table won’t exist.
$current_version = 0;
}
$updates_applied = false;
try {
// Update the schema, one version at a time.
while ($current_version < $target_version) {
$class = $namespace . '\\Migration' . $current_version;
/** @var MigrationInterface $migration */
$migration = new $class;
$migration->upgrade();
$current_version++;
Site::setPreference($schema_name, (string) $current_version);
$updates_applied = true;
}
} catch (PDOException $ex) {
// The schema update scripts should never fail. If they do, there is no clean recovery.
FlashMessages::addMessage($ex->getMessage(), 'danger');
header('Location: site-unavailable.php');
throw $ex;
}
return $updates_applied;
}
/**
* Escape a string for use in a SQL "LIKE" clause
*
* @param string $string
*
* @return string
*/
public static function escapeLike($string) {
return strtr(
$string,
[
'\\' => '\\\\',
'%' => '\%',
'_' => '\_',
]
);
}
}