Commit 9de3b9cb authored by webchick's avatar webchick

#67349 by chx, Damien Tournoud, and paranojik: SQLite support in core! Yeah! :D

parent 842a0fae
......@@ -7,6 +7,7 @@ Drupal 7.0, xxxx-xx-xx (development version)
* Added query builders for INSERT, UPDATE, DELETE, MERGE, and SELECT queries.
* Support for master/slave replication, transactions, multi-insert queries,
delayed inserts, and other features.
* Added support for the SQLite database engine.
- Security:
* Protected cron.php -- cron will only run if the proper key is provided.
* Implemented much stronger password hashes that are also compatible with the
......
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<?php
// $Id$
/**
* @file
* Database interface code for SQLite embedded database engine.
*/
/**
* @ingroup database
* @{
*/
include_once DRUPAL_ROOT . '/includes/database/prefetch.inc';
/**
* Specific SQLite implementation of DatabaseConnection.
*/
class DatabaseConnection_sqlite extends DatabaseConnection {
/**
* Indicates that this connection supports transactions.
*
* @var bool
*/
protected $transactionSupport = TRUE;
public function __construct(Array $connection_options = array()) {
// We don't need a specific PDOStatement class here, we simulate it below.
$connection_options['statement_class'] = FALSE;
$this->transactionSupport = isset($connection_options['transactions']) ? $connection_options['transactions'] : TRUE;
parent::__construct('sqlite:'. $connection_options['database'], '', '', $connection_options);
$this->exec('PRAGMA encoding="UTF-8"');
// Create functions needed by SQLite.
$this->sqliteCreateFunction('if', array($this, 'sqlFunctionIf'));
$this->sqliteCreateFunction('greatest', array($this, 'sqlFunctionGreatest'));
$this->sqliteCreateFunction('pow', 'pow', 2);
$this->sqliteCreateFunction('length', 'strlen', 1);
$this->sqliteCreateFunction('concat', array($this, 'sqlFunctionConcat'));
$this->sqliteCreateFunction('substring', array($this, 'sqlFunctionSubstring'), 3);
$this->sqliteCreateFunction('rand', array($this, 'sqlFunctionRand'));
}
/**
* SQLite compatibility implementation for the IF() SQL function.
*/
public function sqlFunctionIf($condition, $expr1, $expr2 = NULL) {
return $condition ? $expr1 : $expr2;
}
/**
* SQLite compatibility implementation for the GREATEST() SQL function.
*/
public function sqlFunctionGreatest() {
$args = func_get_args();
foreach ($args as $k => $v) {
if (is_null($v)) {
unset($args);
}
}
if (count($args)) {
return max($args);
}
else {
return NULL;
}
}
/**
* SQLite compatibility implementation for the CONCAT() SQL function.
*/
public function sqlFunctionConcat() {
$args = func_get_args();
return implode('', $args);
}
/**
* SQLite compatibility implementation for the SUBSTRING() SQL function.
*/
public function sqlFunctionSubstring($string, $from, $length) {
return substr($string, $from - 1, $length);
}
/**
* SQLite compatibility implementation for the RAND() SQL function.
*/
public function sqlFunctionRand($seed = NULL) {
if (isset($seed)) {
mt_srand($seed);
}
return mt_rand() / mt_getrandmax();
}
/**
* SQLite-specific implementation of DatabaseConnection::prepare().
*
* We don't use prepared statements at all at this stage. We just create
* a DatabaseStatement_sqlite object, that will create a PDOStatement
* using the semi-private PDOPrepare() method below.
*/
public function prepare($query, Array $options = array()) {
return new DatabaseStatement_sqlite($this, $query, $options);
}
/**
* NEVER CALL THIS FUNCTION: YOU MIGHT DEADLOCK YOUR PHP PROCESS.
*
* This is a wrapper around the parent PDO::prepare method. However, as
* the PDO SQLite driver only closes SELECT statements when the PDOStatement
* destructor is called and SQLite does not allow data change (INSERT,
* UPDATE etc) on a table which has open SELECT statements, you should never
* call this function and keep a PDOStatement object alive as that can lead
* to a deadlock. This really, really should be private, but as
* DatabaseStatement_sqlite needs to call it, we have no other choice but to
* expose this function to the world.
*/
public function PDOPrepare($query, Array $options = array()) {
return parent::prepare($query, $options);
}
public function queryRange($query, Array $args, $from, $count, Array $options = array()) {
return $this->query($query . ' LIMIT ' . $from . ', ' . $count, $args, $options);
}
public function queryTemporary($query, Array $args, $tablename, Array $options = array()) {
return $this->query(preg_replace('/^SELECT/i', 'CREATE TEMPORARY TABLE ' . $tablename . ' AS SELECT', $query), $args, $options);
}
public function driver() {
return 'sqlite';
}
public function databaseType() {
return 'sqlite';
}
public function supportsTransactions() {
return $this->transactionSupport;
}
public function mapConditionOperator($operator) {
// We don't want to override any of the defaults.
return NULL;
}
protected function prepareQuery($query) {
// It makes no sense to use the static prepared statement cache here,
// because all the work in our implementation is done in
// DatabaseStatement_sqlite::execute() and cannot be cached.
return $this->prepare($this->prefixTables($query));
}
/**
* @todo Remove this as soon as db_rewrite_sql() has been exterminated.
*/
public function distinctField($table, $field, $query) {
$field_to_select = 'DISTINCT(' . $table . '.' . $field . ')';
// (?<!text) is a negative look-behind (no need to rewrite queries that already use DISTINCT).
return preg_replace('/(SELECT.*)(?:' . $table . '\.|\s)(?<!DISTINCT\()(?<!DISTINCT\(' . $table . '\.)' . $field . '(.*FROM )/AUsi', '\1 ' . $field_to_select . '\2', $query);
}
}
/**
* Specific SQLite implementation of DatabaseConnection.
*
* @see DatabaseConnection_sqlite::PDOPrepare for reasons why we must prefetch
* the data instead of using PDOStatement.
*/
class DatabaseStatement_sqlite extends DatabaseStatementPrefetch implements Iterator, DatabaseStatementInterface {
/**
* SQLite specific implementation of getStatement().
*
* The PDO SQLite layer doesn't replace numeric placeholders in queries
* correctly, and this makes numeric expressions (such as COUNT(*) >= :count)
* fail. We replace numeric placeholders in the query ourselves to work
* around this bug.
*
* See http://bugs.php.net/bug.php?id=45259 for more details.
*/
protected function getStatement($query, &$args = array()) {
if (count($args)) {
// Check if $args is a simple numeric array.
if (range(0, count($args) - 1) === array_keys($args)) {
// In that case, we have unnamed placeholders.
$count = 0;
$new_args = array();
foreach ($args as $value) {
if (is_numeric($value)) {
$query = substr_replace($query, $value, strpos($query, '?'), 1);
}
else {
$placeholder = ':db_statement_placeholder_' . $count++;
$query = substr_replace($query, $placeholder, strpos($query, '?'), 1);
$new_args[$placeholder] = $value;
}
}
$args = $new_args;
}
else {
// Else, this is using named placeholders.
foreach ($args as $placeholder => $value) {
if (is_numeric($value)) {
$query = str_replace($placeholder, $value, $query);
unset($args[$placeholder]);
}
}
}
}
return $this->dbh->PDOPrepare($query);
}
public function execute($args, $options) {
try {
$return = parent::execute($args, $options);
}
catch (PDOException $e) {
if (!empty($e->errorInfo[1]) && $e->errorInfo[1] === 17) {
// The schema has changed. SQLite specifies that we must resend the query.
$return = parent::execute($args, $options);
}
else {
// Rethrow the exception.
throw $e;
}
}
// In some weird cases, SQLite will prefix some column names by the name
// of the table. We post-process the data, by renaming the column names
// using the same convention as MySQL and PostgreSQL.
$rename_columns = array();
foreach ($this->columnNames as $k => $column) {
if (preg_match("/^.*\.(.*)$/", $column, $matches)) {
$rename_columns[$column] = $matches[1];
$this->columnNames[$k] = $matches[1];
}
}
if ($rename_columns) {
foreach ($this->data as $k => $row) {
foreach ($rename_columns as $old_column => $new_column) {
$this->data[$k][$new_column] = $this->data[$k][$old_column];
unset($this->data[$k][$old_column]);
}
}
}
// We will iterate this array so we need to make sure the array pointer is
// at the beginning.
reset($this->data);
return $return;
}
}
/**
* @} End of "ingroup database".
*/
<?php
// $Id$
/**
* @file
* SQLite specific install functions
*/
class DatabaseInstaller_sqlite extends DatabaseInstaller {
protected $pdoDriver = 'sqlite';
public function name() {
return 'SQLite';
}
}
<?php
// $Id $
/**
* @ingroup database
* @{
*/
/**
* SQLite specific implementation of InsertQuery.
*
* We ignore all the default fields and use the clever SQLite syntax:
* INSERT INTO table DEFAULT VALUES
* for degenerated "default only" queries.
*/
class InsertQuery_sqlite extends InsertQuery {
public function execute() {
if (count($this->insertFields) + count($this->defaultFields) == 0) {
return NULL;
}
if (count($this->insertFields)) {
return parent::execute();
}
else {
return $this->connection->query('INSERT INTO {'. $this->table .'} DEFAULT VALUES', array(), $this->queryOptions);
}
}
public function __toString() {
// Produce as many generic placeholders as necessary.
$placeholders = array_fill(0, count($this->insertFields), '?');
return 'INSERT INTO {'. $this->table .'} ('. implode(', ', $this->insertFields) .') VALUES ('. implode(', ', $placeholders) .')';
}
}
/**
* SQLite specific implementation of UpdateQuery.
*
* SQLite counts all the rows that match the conditions as modified, even if they
* will not be affected by the query. We workaround this by ensuring that
* we don't select those rows.
*
* A query like this one:
* UPDATE test SET name = 'newname' WHERE tid = 1
* will become:
* UPDATE test SET name = 'newname' WHERE tid = 1 AND name <> 'newname'
*/
class UpdateQuery_sqlite extends UpdateQuery {
/**
* Helper function that removes the fields that are already in a condition.
*
* @param $fields
* The fields.
* @param QueryConditionInterface $condition
* A database condition.
*/
protected function removeFieldsInCondition(&$fields, QueryConditionInterface $condition) {
foreach ($condition->conditions() as $child_condition) {
if ($child_condition['field'] instanceof QueryConditionInterface) {
$this->removeFieldsInCondition($fields, $child_condition['field']);
}
else {
unset($fields[$child_condition['field']]);
}
}
}
public function execute() {
// Get the fields used in the update query, and remove those that are already
// in the condition.
$fields = $this->expressionFields + $this->fields;
$this->removeFieldsInCondition($fields, $this->condition);
// Add the inverse of the fields to the condition.
$condition = db_or();
foreach ($fields as $field => $data) {
if (is_array($data)) {
// The field is an expression.
$condition->condition($field, $data['expression'], '<>');
// The IS NULL operator is badly managed by DatabaseCondition.
$condition->where($field . ' IS NULL');
}
else if (is_null($data)) {
// The field will be set to NULL.
// The IS NULL operator is badly managed by DatabaseCondition.
$condition->where($field . ' IS NOT NULL');
}
else {
$condition->condition($field, $data, '<>');
// The IS NULL operator is badly managed by DatabaseCondition.
$condition->where($field . ' IS NULL');
}
}
if (count($condition)) {
$condition->compile($this->connection);
$this->condition->where((string) $condition, $condition->arguments());
}
return parent::execute();
}
}
/**
* SQLite specific implementation of DeleteQuery.
*
* When the WHERE is omitted from a DELETE statement and the table being deleted
* has no triggers, SQLite uses an optimization to erase the entire table content
* without having to visit each row of the table individually.
*
* Prior to SQLite 3.6.5, SQLite does not return the actual number of rows deleted
* by that optimized "truncate" optimization.
*/
class DeleteQuery_sqlite extends DeleteQuery {
public function execute() {
if (!count($this->condition)) {
$total_rows = $this->connection->query('SELECT COUNT(*) FROM {' . $this->connection->escapeTable($this->table) . '}')->fetchField();
parent::execute();
return $total_rows;
}
else {
return parent::execute();
}
}
}
/**
* @} End of "ingroup database".
*/
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