<?php
/**
* @package SQLite Integration
* @author Kojima Toshiyasu, Justin Adie
*/
/**
* Provides a class for rewriting create queries
* this class borrows its inspiration from the work done on tikiwiki.
*/
class CreateQuery{
private $_query = '';
private $index_queries = array();
private $_errors = array();
private $table_name = '';
private $has_primary_key = false;
/**
* initialises the object properties
* @param string $query the query being processed
* @return string|array the processed (rewritten) query
*/
public function rewrite_query($query){
$this->_query = $query;
$this->_errors [] = '';
if (preg_match('/^CREATE\\s*(UNIQUE|FULLTEXT|)\\s*INDEX/ims', $this->_query, $match)) {
if (isset($match[1]) && stripos($match[1], 'fulltext') !== false) {
return 'SELECT 1=1';
} else {
return $this->_query;
}
} elseif (preg_match('/^CREATE\\s*(TEMP|TEMPORARY|)\\s*TRIGGER\\s*/im', $this->_query)) {
return $this->_query;
}
$this->get_table_name();
$this->rewrite_comments();
$this->rewrite_field_types();
$this->rewrite_character_set();
$this->rewrite_engine_info();
$this->rewrite_unsigned();
$this->rewrite_autoincrement();
$this->rewrite_primary_key();
$this->rewrite_unique_key();
$this->rewrite_enum();
$this->rewrite_set();
$this->rewrite_key();
$this->add_if_not_exists();
$this->strip_backticks();
return $this->post_process();
}
/**
* Method for getting the table name from the create query.
* taken from PDO for WordPress
* we don't need 'IF NOT EXISTS', so we changed the pattern.
*/
private function get_table_name(){
// $pattern = '/^\\s*CREATE\\s*(TEMP|TEMPORARY)?\\s*TABLE\\s*(IF NOT EXISTS)?\\s*([^\(]*)/imsx';
$pattern = '/^\\s*CREATE\\s*(?:TEMP|TEMPORARY)?\\s*TABLE\\s*(?:IF\\s*NOT\\s*EXISTS)?\\s*([^\(]*)/imsx';
if (preg_match($pattern, $this->_query, $matches)) {
$this->table_name = trim($matches[1]);
}
}
/**
* Method for changing the field type to SQLite compatible type.
*/
private function rewrite_field_types(){
$array_types = array (
'bit' => 'integer', 'bool' => 'integer',
'boolean' => 'integer', 'tinyint' => 'integer',
'smallint' => 'integer', 'mediumint' => 'integer',
'int' => 'integer', 'integer' => 'integer',
'bigint' => 'integer', 'float' => 'real',
'double' => 'real', 'decimal' => 'real',
'dec' => 'real', 'numeric' => 'real',
'fixed' => 'real', 'date' => 'text',
'datetime' => 'text', 'timestamp' => 'text',
'time' => 'text', 'year' => 'text',
'char' => 'text', 'varchar' => 'text',
'binary' => 'integer', 'varbinary' => 'blob',
'tinyblob' => 'blob', 'tinytext' => 'text',
'blob' => 'blob', 'text' => 'text',
'mediumblob' => 'blob', 'mediumtext' => 'text',
'longblob' => 'blob', 'longtext' => 'text'
);
foreach ($array_types as $o=>$r){
$pattern = "/\\b(?<!`)$o\\b\\s*(\([^\)]*\)*)?\\s*/ims";
if (preg_match("/^\\s*.*?\\s*\(.*?$o.*?\)/im", $this->_query)) {
;
} else {
$this->_query = preg_replace($pattern, " $r ", $this->_query);
}
}
}
/**
* Method for stripping the comments from the SQL statement
*/
private function rewrite_comments(){
$this->_query = preg_replace("/# --------------------------------------------------------/","-- ******************************************************",$this->_query);
$this->_query = preg_replace("/#/","--",$this->_query);
}
/**
* Method for stripping the engine and other stuffs
*/
private function rewrite_engine_info(){
$this->_query = preg_replace("/\\s*(TYPE|ENGINE)\\s*=\\s*.*(?<!;)/ims",'',$this->_query);
$this->_query = preg_replace("/ AUTO_INCREMENT\\s*=\\s*[0-9]*/ims",'',$this->_query);
}
/**
* Method for stripping unsigned
*/
private function rewrite_unsigned(){
$this->_query = preg_replace('/\\bunsigned\\b/ims', ' ', $this->_query);
}
/**
* Method for rewriting auto_increment
* if the field type is 'integer primary key', it is automatically autoincremented
*/
private function rewrite_autoincrement(){
$this->_query = preg_replace('/\\bauto_increment\\s*primary\\s*key\\s*(,)?/ims', ' PRIMARY KEY AUTOINCREMENT \\1', $this->_query, -1, $count);
$this->_query = preg_replace('/\\bauto_increment\\b\\s*(,)?/ims', ' PRIMARY KEY AUTOINCREMENT $1', $this->_query, -1, $count);
if ($count > 0){
$this->has_primary_key = true;
}
}
/**
* Method for rewriting primary key
*/
private function rewrite_primary_key(){
if ($this->has_primary_key) {
$this->_query = preg_replace('/\\bprimary key\\s*\([^\)]*\)/ims', ' ', $this->_query);
} else {
// If primary key has an index name, we remove that name.
$this->_query = preg_replace('/\\bprimary\\s*key\\s*.*?\\s*(\(.*?\))/im', 'PRIMARY KEY \\1', $this->_query);
}
}
/**
* Method for rewriting unique key
*/
private function rewrite_unique_key(){
$this->_query = preg_replace_callback('/\\bunique key\\b([^\(]*)(\([^\)]*\))/ims', array($this, '_rewrite_unique_key'), $this->_query);
}
/**
* Callback method for rewrite_unique_key
* @param array $matches an array of matches from the Regex
*/
private function _rewrite_unique_key($matches){
$index_name = trim($matches[1]);
$col_name = trim($matches[2]);
$tbl_name = $this->table_name;
$_wpdb = new PDODB();
$results = $_wpdb->get_results("SELECT name FROM sqlite_master WHERE type='index'");
$_wpdb = null;
if ($results) {
foreach ($results as $result) {
if ($result->name == $index_name) {
$r = rand(0, 50);
$index_name = $index_name . "_$r";
break;
}
}
}
$index_name = str_replace(' ', '', $index_name);
$this->index_queries[] = "CREATE UNIQUE INDEX $index_name ON " . $tbl_name .$col_name;
return '';
}
/**
* Method for handling ENUM fields
* SQLite doesn't support enum, so we change it to check constraint
*/
private function rewrite_enum(){
$pattern = '/(,|\))([^,]*)enum\((.*?)\)([^,\)]*)/ims';
$this->_query = preg_replace_callback($pattern, array($this, '_rewrite_enum'), $this->_query);
}
/**
* Method for the callback function rewrite_enum and rewrite_set
*/
private function _rewrite_enum($matches){
$output = $matches[1] . ' ' . $matches[2]. ' TEXT '. $matches[4].' CHECK ('.$matches[2].' IN ('.$matches[3].')) ';
return $output;
}
/**
* Method for rewriting usage of set
* whilst not identical to enum, they are similar and sqlite does not
* support either.
*/
private function rewrite_set(){
$pattern = '/\b(\w)*\bset\\s*\((.*?)\)\\s*(.*?)(,)*/ims';
$this->_query = preg_replace_callback($pattern, array($this, '_rewrite_enum'), $this->_query);
}
/**
* Method for rewriting usage of key to create an index
* sqlite cannot create non-unique indices as part of the create query
* so we need to create an index by hand and append it to the create query
*/
private function rewrite_key(){
$this->_query = preg_replace_callback('/,\\s*(KEY|INDEX)\\s*(\\w+)?\\s*(\(.*(?<!\\d)\))/im', array($this, '_rewrite_key'), $this->_query);
}
/**
* Callback method for rewrite_key
* @param array $matches an array of matches from the Regex
*/
private function _rewrite_key($matches){
$index_name = trim($matches[2]);
$col_name = trim($matches[3]);
if (preg_match('/\([0-9]+?\)/', $col_name, $match)) {
$col_name = preg_replace_callback('/\([0-9]+?\)/', array($this, '_remove_length'), $col_name);
}
$tbl_name = $this->table_name;
$_wpdb = new PDODB();
$results = $_wpdb->get_results("SELECT name FROM sqlite_master WHERE type='index'");
$_wpdb = null;
if ($results) {
foreach ($results as $result) {
if ($result->name == $index_name) {
$r = rand(0, 50);
$index_name = $index_name . "_$r";
break;
}
}
}
$this->index_queries[] = 'CREATE INDEX '. $index_name . ' ON ' . $tbl_name . $col_name ;
return '';
}
private function _remove_length($match) {
return '';
}
/**
* Method to assemble the main query and index queries into an array
* to be returned to the base class
* @return array
*/
private function post_process(){
$mainquery = $this->_query;
do{
$count = 0;
$mainquery = preg_replace('/,\\s*\)/imsx',')', $mainquery, -1, $count);
} while ($count > 0);
do {
$count = 0;
$mainquery = preg_replace('/\(\\s*?,/imsx', '(', $mainquery, -1, $count);
} while ($count > 0);
$return_val[] = $mainquery;
$return_val = array_merge($return_val, $this->index_queries);
return $return_val;
}
/**
* Method to add IF NOT EXISTS to query defs
* sometimes, if upgrade.php is being called, wordpress seems to want to run
* new create queries. this stops the query from throwing an error and halting
* output
*/
private function add_if_not_exists(){
$pattern_table = '/^\\s*CREATE\\s*(TEMP|TEMPORARY)?\\s*TABLE\\s*(IF NOT EXISTS)?\\s*/ims';
$this->_query = preg_replace($pattern_table, 'CREATE $1 TABLE IF NOT EXISTS ', $this->_query);
$pattern_index = '/^\\s*CREATE\\s*(UNIQUE)?\\s*INDEX\\s*(IF NOT EXISTS)?\\s*/ims';
for ($i = 0; $i < count($this->index_queries); $i++) {
$this->index_queries[$i] = preg_replace($pattern_index, 'CREATE $1 INDEX IF NOT EXISTS ', $this->index_queries[$i]);
}
}
/**
* Method to strip back ticks
*/
private function strip_backticks(){
$this->_query = str_replace('`', '', $this->_query);
foreach ($this->index_queries as &$query) {
$query = str_replace('`', '', $query);
}
}
/**
* Method to remove the character set information from within mysql queries
*/
private function rewrite_character_set(){
$pattern_charset = '/\\b(default\\s*character\\s*set|default\\s*charset|character\\s*set)\\s*(?<!\()[^ ]*/im';
$pattern_collate1 = '/\\s*collate\\s*[^ ]*(?=,)/im';
$pattern_collate2 = '/\\s*collate\\s*[^ ]*(?<!;)/im';
$patterns = array($pattern_charset, $pattern_collate1, $pattern_collate2);
$this->_query = preg_replace($patterns, '', $this->_query);
}
}