/**
* Function to handle ALTER COLUMN.
*
* @access private
* @param array of string $queries
* @return string|array of string
*/
private function handle_alter_command($queries)
{
$tokenized_query = $queries;
$temp_table = 'temp_' . $tokenized_query['table_name'];
if (isset($tokenized_query['default_value'])) {
$def_value = $this->convert_field_types($tokenized_query['column_name'], $tokenized_query['default_value']);
$def_value = 'DEFAULT ' . $def_value;
} else {
$def_value = null;
}
$_wpdb = new PDODB();
$query_obj = $_wpdb->get_results("SELECT sql FROM sqlite_master WHERE tbl_name='{$tokenized_query['table_name']}'");
$_wpdb = null;
for ($i = 0; $i < count($query_obj); $i++) {
$index_queries[$i] = $query_obj[$i]->sql;
}
$create_query = array_shift($index_queries);
if (stripos($create_query, $tokenized_query['column_name']) === false) {
return 'SELECT 1=1';
}
if (preg_match("/\\s*({$tokenized_query['column_name']})\\s*(.*)?(DEFAULT\\s*.*)[,)]/im", $create_query, $match)) {
$col_name = trim($match[1]);
$col_def = trim($match[2]);
$col_def_esc = str_replace(array('(', ')'), array('\\(', '\\)'), $col_def);
$checked_col_def = $this->convert_field_types($col_name, $col_def);
$old_default = trim($match[3]);
$pattern = "/{$col_name}\\s*{$col_def_esc}\\s*{$old_default}/im";
if (is_null($def_value)) {
$replacement = $col_name . ' ' . $checked_col_def;
} else {
$replacement = $col_name . ' ' . $checked_col_def . ' ' . $def_value;
}
$create_query = preg_replace($pattern, $replacement, $create_query);
$create_query = str_ireplace($tokenized_query['table_name'], $temp_table, $create_query);
} elseif (preg_match("/\\s*({$tokenized_query['column_name']})\\s*(.*)?[,)]/im", $create_query, $match)) {
$col_name = trim($match[1]);
$col_def = trim($match[2]);
$col_def_esc = str_replace(array('(', ')'), array('\\(', '\\)'), $col_def);
$checked_col_def = $this->convert_field_types($col_name, $col_def);
$pattern = "/{$col_name}\\s*{$col_def_esc}/im";
if (is_null($def_value)) {
$replacement = $col_name . ' ' . $checked_col_def;
} else {
$replacement = $col_name . ' ' . $checked_col_def . ' ' . $def_value;
}
$create_query = preg_replace($pattern, $replacement, $create_query);
$create_query = str_ireplace($tokenized_query['table_name'], $temp_table, $create_query);
} else {
return 'SELECT 1=1';
}
$query[] = $create_query;
$query[] = "INSERT INTO {$temp_table} SELECT * FROM {$tokenized_query['table_name']}";
$query[] = "DROP TABLE IF EXISTS {$tokenized_query['table_name']}";
$query[] = "ALTER TABLE {$temp_table} RENAME TO {$tokenized_query['table_name']}";
foreach ($index_queries as $index) {
$query[] = $index;
}
return $query;
}
/**
* Method to avoid DELETE with JOIN statement.
*
* wp-admin/includes/upgrade.php contains 'DELETE ... JOIN' statement.
* This query can't be replaced with regular expression or udf, so we
* replace all the statement with another. But this query was used in
* the very old version of WordPress when it was upgraded. So we won't
* have no chance that this method should be used.
*
* @access private
*/
private function delete_workaround()
{
global $wpdb;
$pattern = "DELETE o1 FROM {$wpdb->options} AS o1 JOIN {$wpdb->options} AS o2";
$pattern2 = "DELETE a, b FROM {$wpdb->sitemeta} AS a, {$wpdb->sitemeta} AS b";
$rewritten = "DELETE FROM {$wpdb->options} WHERE option_id IN (SELECT MIN(option_id) FROM {$wpdb->options} GROUP BY option_name HAVING COUNT(*) > 1)";
if (stripos($this->_query, $pattern) !== false) {
$this->_query = $rewritten;
} else {
if (stripos($this->_query, $pattern2) !== false) {
$time = time();
$prep_query = "SELECT a.meta_id AS aid, b.meta_id AS bid FROM {$wpdb->sitemeta} AS a INNER JOIN {$wpdb->sitemeta} AS b ON a.meta_key='_site_transient_timeout_'||substr(b.meta_key, 17) WHERE b.meta_key='_site_transient_'||substr(a.meta_key, 25) AND a.meta_value < {$time}";
$_wpdb = new PDODB();
$ids = $_wpdb->get_results($prep_query);
foreach ($ids as $id) {
$ids_to_delete[] = $id->aid;
$ids_to_delete[] = $id->bid;
}
$rewritten = "DELETE FROM {$wpdb->sitemeta} WHERE meta_id IN (" . implode(',', $ids_to_delete) . ")";
$this->_query = $rewritten;
}
}
}
/**
* Callback method for rewrite_key.
*
* @param array $matches an array of matches from the Regex
* @access private
*/
private function _rewrite_key($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 '';
}
