/**
* Search and replace strings in the entire database.
* Used for xhtml upgrade, but can also be used, for eg, to change links.
* This function prints every query
* (Adapted from moodle function of same name)
*
* @param array $replacearray keys = search, values = replacements.
*/
function db_replace($replacearray)
{
global $db;
/// Turn off time limits, sometimes upgrades can be slow.
@set_time_limit(0);
@ob_implicit_flush(true);
while (@ob_end_flush()) {
}
if (!($tables = $db->Metatables())) {
// No tables yet at all.
return false;
}
foreach ($tables as $table) {
if (in_array($table, array('config', 'adodb_logsql'))) {
// Don't process these
continue;
}
if ($columns = $db->MetaColumns($table, false)) {
$db->debug = true;
foreach ($columns as $column => $data) {
if (in_array($data->type, array('text', 'mediumtext', 'longtext', 'varchar'))) {
// Text stuff only
foreach ($replacearray as $s => $r) {
$db->execute('UPDATE ' . db_quote_table_placeholders('{' . $table . '}') . '
SET ' . db_quote_identifier($column) . ' = REPLACE(' . db_quote_identifier($column) . ', ?, ?)', array($s, $r));
}
}
}
$db->debug = false;
}
}
}
/**
* Reset all database tables to default values.
* @static
* @return bool true if reset done, false if skipped
*/
public static function reset_database()
{
$tables = get_tables_from_xmldb();
$prefix = get_config('dbprefix');
if (!table_exists(new XMLDBTable('config'))) {
// not installed yet
return false;
}
if (!($data = self::get_tabledata())) {
// not initialised yet
return false;
}
if (!($structure = self::get_tablestructure())) {
// not initialised yet
return false;
}
$unmodifiedorempties = self::guess_unmodified_empty_tables();
db_begin();
// Temporary drop current foreign key contraints
$foreignkeys = array();
foreach ($tables as $table) {
$tablename = $table->getName();
$foreignkeys = array_merge($foreignkeys, get_foreign_keys($tablename));
}
// Drop foreign key contraints
if (is_mysql()) {
foreach ($foreignkeys as $key) {
execute_sql('ALTER TABLE ' . db_quote_identifier($key['table']) . ' DROP FOREIGN KEY ' . db_quote_identifier($key['constraintname']));
}
} else {
foreach ($foreignkeys as $key) {
execute_sql('ALTER TABLE ' . db_quote_identifier($key['table']) . ' DROP CONSTRAINT IF EXISTS ' . db_quote_identifier($key['constraintname']));
}
}
foreach ($tables as $table) {
$tablename = $table->getName();
if (isset($unmodifiedorempties[$tablename])) {
continue;
}
if (!isset($data[$tablename])) {
continue;
}
// Empty the table
execute_sql('DELETE FROM {' . $tablename . '}');
// Restore the table from the backup file
if ($data[$tablename]) {
foreach ($data[$tablename] as $record) {
insert_record($tablename, $record);
if ($tablename == 'usr' && $record->username == 'root' && is_mysql()) {
// gratuitous mysql workaround
set_field('usr', 'id', 0, 'username', 'root');
execute_sql('ALTER TABLE {usr} AUTO_INCREMENT=1');
}
}
}
}
// Re-add foreign key contraints
foreach ($foreignkeys as $key) {
execute_sql('ALTER TABLE ' . db_quote_identifier($key['table']) . ' ADD CONSTRAINT ' . db_quote_identifier($key['constraintname']) . ' FOREIGN KEY ' . '(' . implode(',', array_map('db_quote_identifier', $key['fields'])) . ')' . ' REFERENCES ' . db_quote_identifier($key['reftable']) . '(' . implode(',', array_map('db_quote_identifier', $key['reffields'])) . ')');
}
db_commit();
// reset all next record ids - aka sequences
self::reset_all_database_sequences($unmodifiedorempties);
return true;
}
