+ /**
+ * @brief Delete a row from a table
+ *
+ * @param string $table Table name
+ * @param array $param parameter array
+ * @param boolean $in_process Internal use: Only do a commit after the last delete
+ * @param array $callstack Internal use: prevent endless loops
+ *
+ * @return boolean|array was the delete successfull? When $in_process is set: deletion data
+ */
+ public static function delete($table, $param, $in_process = false, &$callstack = array()) {
+
+ $commands = array();
+
+ // Create a key for the loop prevention
+ $key = $table.':'.implode(':', array_keys($param)).':'.implode(':', $param);
+
+ // We quit when this key already exists in the callstack.
+ if (isset($callstack[$key])) {
+ return $commands;
+ }
+
+ $callstack[$key] = true;
+
+ $table = self::$dbo->escape($table);
+
+ $commands[$key] = array('table' => $table, 'param' => $param);
+
+ // To speed up the whole process we cache the table relations
+ if (count(self::$relation) == 0) {
+ self::build_relation_data();
+ }
+
+ // Is there a relation entry for the table?
+ if (isset(self::$relation[$table])) {
+ // We only allow a simple "one field" relation.
+ $field = array_keys(self::$relation[$table])[0];
+ $rel_def = array_values(self::$relation[$table])[0];
+
+ // Create a key for preventing double queries
+ $qkey = $field.'-'.$table.':'.implode(':', array_keys($param)).':'.implode(':', $param);
+
+ // When the search field is the relation field, we don't need to fetch the rows
+ // This is useful when the leading record is already deleted in the frontend but the rest is done in the backend
+ if ((count($param) == 1) && ($field == array_keys($param)[0])) {
+ foreach ($rel_def AS $rel_table => $rel_fields) {
+ foreach ($rel_fields AS $rel_field) {
+ $retval = self::delete($rel_table, array($rel_field => array_values($param)[0]), true, $callstack);
+ $commands = array_merge($commands, $retval);
+ }
+ }
+ // We quit when this key already exists in the callstack.
+ } elseif (!isset($callstack[$qkey])) {
+
+ $callstack[$qkey] = true;
+
+ // Fetch all rows that are to be deleted
+ $data = self::select($table, array($field), $param);
+
+ while ($row = self::fetch($data)) {
+ // Now we accumulate the delete commands
+ $retval = self::delete($table, array($field => $row[$field]), true, $callstack);
+ $commands = array_merge($commands, $retval);
+ }
+
+ self::close($data);
+
+ // Since we had split the delete command we don't need the original command anymore
+ unset($commands[$key]);
+ }
+ }
+
+ if (!$in_process) {
+ // Now we finalize the process
+ $do_transaction = !self::$in_transaction;
+
+ if ($do_transaction) {
+ self::transaction();
+ }
+
+ $compacted = array();
+ $counter = array();
+
+ foreach ($commands AS $command) {
+ $condition = $command['param'];
+ $array_element = each($condition);
+ $array_key = $array_element['key'];
+ if (is_int($array_key)) {
+ $condition_string = " WHERE ".array_shift($condition);
+ } else {
+ $condition_string = " WHERE `".implode("` = ? AND `", array_keys($condition))."` = ?";
+ }
+
+ if ((count($command['param']) > 1) || is_int($array_key)) {
+ $sql = "DELETE FROM `".$command['table']."`".$condition_string;
+ logger(self::replace_parameters($sql, $condition), LOGGER_DATA);
+
+ if (!self::e($sql, $condition)) {
+ if ($do_transaction) {
+ self::rollback();
+ }
+ return false;
+ }
+ } else {
+ $key_table = $command['table'];
+ $key_param = array_keys($command['param'])[0];
+ $value = array_values($command['param'])[0];
+
+ // Split the SQL queries in chunks of 100 values
+ // We do the $i stuff here to make the code better readable
+ $i = $counter[$key_table][$key_param];
+ if (count($compacted[$key_table][$key_param][$i]) > 100) {
+ ++$i;
+ }
+
+ $compacted[$key_table][$key_param][$i][$value] = $value;
+ $counter[$key_table][$key_param] = $i;
+ }
+ }
+ foreach ($compacted AS $table => $values) {
+ foreach ($values AS $field => $field_value_list) {
+ foreach ($field_value_list AS $field_values) {
+ $sql = "DELETE FROM `".$table."` WHERE `".$field."` IN (".
+ substr(str_repeat("?, ", count($field_values)), 0, -2).");";
+
+ logger(self::replace_parameters($sql, $field_values), LOGGER_DATA);
+
+ if (!self::e($sql, $field_values)) {
+ if ($do_transaction) {
+ self::rollback();
+ }
+ return false;
+ }
+ }
+ }
+ }
+ if ($do_transaction) {
+ self::commit();
+ }
+ return true;
+ }
+
+ return $commands;