Scalr\Model\AbstractEntity::_prepareSaveStatement PHP Method

    private function _prepareSaveStatement()
    {
        $stmt = new EntityStatement($this->db(), get_class($this));
        /* @var $iterator EntityPropertiesIterator */
        $iterator = $this->getIterator();
        $pk = $iterator->getPrimaryKey();
        if (empty($pk)) {
            throw new ModelException("Primary key has not been defined with @Id tag for " . get_class($this));
        }
        $stmtPk = [];
        $stmtFields = [];
        $stmtUpdate = [];
        $args = [];
        $pkArgs = [];
        $onDuplicateArgs = [];
        /* @var $field Field */
        foreach ($iterator->fields() as $field) {
            $stmtFields[] = "{$field->getColumnName()} = {$field->type->wh()}";
            $args[] = $field;
            if (isset($field->id)) {
                //Field takes a part in primary key
                $stmtPk[] = "{$field->getColumnName()} = {$field->type->wh()}";
                $pkArgs[] = $field;
            } else {
                $stmtUpdate[] = "{$field->getColumnName()} = {$field->type->wh()}";
                $onDuplicateArgs[] = $field;
            }
        }
        $stmtFields = implode(", ", $stmtFields);
        $table = static::table();
        if ($this->_hasUniqueIndex()) {
            $stmt->setInsertStatement(static::db()->Prepare("INSERT INTO {$table} SET {$stmtFields} "), $args);
        } else {
            $stmt->setInsertStatement(static::db()->Prepare("INSERT INTO {$table} SET {$stmtFields}" . (empty($stmtUpdate) ? '' : " ON DUPLICATE KEY UPDATE " . implode(", ", $stmtUpdate))), array_merge($args, $onDuplicateArgs));
        }
        if (!empty($stmtPk)) {
            $stmtPk = implode(" AND ", $stmtPk);
            $stmt->setUpdateStatement(static::db()->Prepare("UPDATE {$table} SET {$stmtFields} WHERE {$stmtPk} LIMIT 1"), array_merge($args, $pkArgs));
            $stmt->setDeleteStatement(static::db()->Prepare("DELETE FROM {$table} WHERE {$stmtPk} LIMIT 1"), $pkArgs);
        }
        return $stmt;
    }